How to recover your data when rebuilding, restoring and upgrading fails

When rebuilding, restoring and upgrading fails, you can recover your data. Outlook stores your data in the Data Records folder in your Identity folder.

~/Documents/Microsoft User Data/Office 2011 Identities/Main Identity/Data Records

If you restore your Identity from Time Machine or another backup and it fails to rebuild, or you upgraded to Service Pack 2 (SP2) 14.2.1 and you have missing data you can restore your data from your old Identity. ALWAYS WORK OFF A COPY [Note: Since posting this article, we have discovered an option that has had great success in recovering Identities. See Outlook rebuild results in folders named Recovered. This method has been successful in all types of rebuild issues. -18000, error 255, fails to rebuild etc]

    1. Upgrade to Service Pack 2 (SP2) 14.2.1 or later See this article for details.
    2. Create a new blank SP2 Identity.
    3. Quit Outlook.
      1. Some users have found that deleting the database file in the new Identity helped.
    4. COPY these Data Records folders from the old Identity to the new blank Identity replacing the new folders. Do NOT replace the root Data Records folder. Only the sub-folders listed here.
      • Contacts
      • Events
      • Folders (one user reported replace Categories (not folders) worked better)
      • Mail Accounts
      • Message Attachments
      • Message Sources
      • Messages
      • Note
      • Signatures
      • Signature Attachments
    5. Select to rebuild the Identity in Database Utility.
    6. Open Outlook and your data should be back.

Note: Some users have found that folders were named “Recovered folder” after rebuilding using this option. I posted a new recovery option here that has been very successful. It has worked for multiple types of rebuild errors. Even if you don’t see the Recovered folder issue, this process is definitely worth trying. Except for the setup process, this new option is much simpler.

Outlook rebuild results in folders named Recovered


How to create a new Identity


How to set Identity as Default

1.  Open the Microsoft Database Utility.

How to Rebuild your Outlook database

1.  Open the Microsoft Database Utility.

2.  Click the identity of the database that you want to rebuild, and then click Rebuild.

Before the Database Utility rebuilds a database, it creates a backup copy of your database and moves it into a folder in the /Users/username/Documents/Microsoft User Data/Office 2011 Identities/ folder. The backup copy displays the date and time the backup was created. Example:  Main [Backed up 5-05-2012 13.35] You can delete this Identity after you are satisfied with the rebuild.

How to re-index your Outlook Identity Spotlight cache files.

  1. From the Apple menu, choose System Preferences.
  2. Click Spotlight.
  3. Make sure Mail Messages is checked under the Search Results tab.
  4. Click the Privacy tab. * Drag your Identity to the list. Wait a couple of minutes.
  5. Remove your identity.
  6. Spotlight will re-index the contents of your identity.

You can tell if it’s still in progress by simply looking at the Spotlight menu: There’s a blinking dot in the middle of the magnifying glass while indexing is occurring.

You can also monitor the mdworker32 file in Activity Monitor to see it’s active. Enter mdworker32 in the search filter to easily monitor.

Enter mdworker32 in the search filter

Until this process is finished, Spotlight won’t know the contents of your disks and neither will Outlook. All lists like contacts, events, notes etc. are generated by the Spotlight searches.

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79 comments to How to recover your data when rebuilding, restoring and upgrading fails

  • Steve C

    I have found that this issue is most commonly a result of the ACL (access control list) being mis-associated with the MS User Account Data for the original profile.

    I’ve had quite a bit of luck with this command:
    sudo chown -R -P :Group /Users/

    where is the short name of the user who should now own the data. Might not help every time, but it has saved me from needing to re-create profiles every time I run across this issue.

    [Note: this is for admins]

  • Leigh

    I want to thank you for your clear, concise, and very detailed explanation on how to recover these files. I was tasked 3 days ago to recover a previous employee’s Outlook data from a Time Machine back-up. I have spent 3 days of work and personal time trying so many suggestions from forums, MS, and Mac friends. Your procedures have been the only ones to work. I am so grateful. Please keep up the outstanding work!!

    Leigh in Durham, NC

  • Mark

    Thank you for this helpful set of instructions. I have followed them, and have gotten Outlook back up and running without losing data! However, now the Send/Receive function is not working properly. I have two email accounts on my Outlook. One is a Gmail, the other through Comcast which is a POP account. Before, when I opened Outlook, it would automatically go through a Send/Receive cycle for both accounts. Or, if I clicked the Send/Receive button, it would do likewise. Now, there does not appear to be an auto Send/Receive for my Comcast account when I start out Outlook. Similarly, when I click the button, it does not appear to access my Comcast account. Only if I click on the Tools menu, and then click Send and Receive under that menu, and then click “Comcast” will it download my Comcast messages. Any suggestions?

  • Mark

    Thanks, Diane. I went ahead, removed the accounts, and added them back in. And it now seems to be working. Much appreciated.

  • John

    I was able to rebuild my identity, thanks for your instructions. I had to take it over to a more powerful computer to do so. Only problem is that by very specific folder structure was washed out and I now have 1057 sequential folders named “Recovery Folder #__”.

    Do you have any suggestions on how to get the folder structure back?

    The Original identity that I have on a time machine backup is from Outlook 2011 version 14.2.4. It was rebuild on a more powerful computer that is running 14.1

    • You need to update the computer with 14.1.0 to 14.2.0 THEN rebuild. I’m surprised that it was even able to recover anything in 14.2.4.

      [edited] Since posting these instructions, we have found that rebuilding in 14.1 as described in Outlook rebuild results in folders named Recovered works for most issues with an SP2 Identity. Once an Identity has been rebuilt, chances for a good recovery especially getting folder names back once they have been named “recovered” fail. You need to work off the original Identity BEFORE you tried rebuilding. Recovered Identities from Time Machine work great with this option since the database nor the folder “Database Headers” are needed.

      Always make a copy of the Identity before you rebuild in case you need to try a different option. I suspect the database is kaput now.

  • Andy

    I am stuck. Trying to rebuild database in 14.2.4 from a Time Machine restore. Have tried creating a new identity and moving the 9 specified folders to the data folder then rebuilding (I don’t have a Note folder). I have even tried moving the identity folder to a 1TB drive and putting an alias back in the main Identities folder. Nothing at all returns anything other than “your database could not be rebuilt” after approx 27 minutes of crunching. I have even tried starting the machine in safe mode and running NO other apps in the background.

    What else can I try?

    • Moving the Identity to the larger drive then aliasing back will not work. You would need be able to boot from the larger drive in order to get the benefit from more space. YOu would need to install OS X and Office 2011 or make a clone on the drive THEN boot from the larger drive to rebuild.

      I can’t guarantee this will work either. I suggest getting a fresh backup from Time Machine to try the rebuild or if your Identity will open, move to a new Identity as described in the link below.

      What type of account(s)? (POP, IMAP, Exchange) If your data is IMAP or Exchange you can simply download from the server again. It’s mail under “On My Computer” from POP accounts or mail moved from server to “On My Computer” folders that’s subject to loss. Did you try the options here?

      How to move your data to a new Identity

  • Dave Jane

    I cannot get my database rebuilt. I followed the instructions above, but when I get to copying the “message source” folder it get’s to 5.77gb of 6.17gb then gives me the following error message:

    The Finder can’t complete the operation because some data in “x27_96241.olk14MsgSource” can’t be read or written.
    (Error code -36)

    I use Time Machine every day this happened to me while I was on a two week business trip, so my last backup to restore from is about 15 days old! Also, unfortunately I use POP mail so only place my mail is stored is locally.

    Have I lost 2 whole weeks of mail??

    • Error -36 is a hardware error. If you get this error when copying between hard drives you should start to worry. An I/O error almost always means disk damage (hard drive, optical drive, CD).Try running Disk Utility > Repair Disk. Disk Utility can be found in Applications/Utilities.

      Is the Identity folder you are trying to recover on an external drive? Are you copying the Identity folder or just the Message Sources folder?

      Using POP is subject to loss. There is often no way to recover when POP Identities fail. Sorry!

      I highly suggest you move to IMAP or Exchange.

  • Dave Jane

    Ironically I’d just been looking recently to change over to IMAP 🙁

    It’s all on my hard drive (local, not external). I tried copying the whole Identity Folder first and it failed so then I went one at a time to narrow down where corruption was.

    Frustrating part is that Outlook will open and show me all the mail, but the “database needs rebuilding” box comes up over the top and I can’t click on Outlook itself. Only cancel or rebuild.

    I tried Repair Disk, and Repair Disk Permissions. That gave me this message once it was done:

    “Warning SUID file “System/Library/CoreServices/RemoteManagement/” has been modified and will not be repaired”

    • That error sounds like the one error that everyone sees.

      Let’s see if we can delete the file: x27_96241.olk14MsgSource. Outlook must be quit.

      In the Identity, go to the Message Sources folder.

      Drill down to the folder 27K
      Scroll down until you find x27_96241
      When you open Outlook it will ask you to rebuild. It’s possible getting rid of this file will allow Outlook to rebuild or you can move the folder to a new Identity as described in the article and see if it rebuilds there.

      Always work off a copy!

  • Dave Jane

    I had the same idea.
    I created a new identity. Copied everything into that new file (over 6GB) except for this one troublesome file – x27_96241.olk14MsgSource (9.7mb in folder Message Sources/0T/0B/0M/96K)
    Opened Outlook in the new identity and it opened but there was NOTHING in there. As if it was a brand new use of the program. Didn’t even ask me to rebuild.

  • Dave Jane

    Finally got to my Time Machine Drive and found that the folder that file was in (96K) was the same as before I’d left on my trip. Simply copied it over into the new identity, ran the database rebuilder, and everything is back up and working again.
    Thanks, Diane, for the advice.

  • Rob

    Hello Diane, seems like you’re the person that may probably be able to solve my problem.

    After upgrading to 14.2.4 I am now unable to open Outlook. When i click on the outlook icon in the dock, Outlook appears to be starting for about 5-10 seconds while displaying “setting up identity” and then the application just terminates without giving any error messages.

    I tried all the steps in this document above (several times) and it reaches halfway through step 5 of 5 and then i get the following error message.
    “Your database could not be rebuilt. [-18000]”

    I’d like to mention that every time i’ve tried your steps above, it has taken me approximately about an hour to complete. My identity folder is 12.7 GB. However, my identity folder does not contain either the “Note” subfolder or the “Signature Attachments” subfolder.

    Plz tell me you can help!!

    • Open the in Applications/Utilities. In the top filter, enter Outlook. Do you see error 255? If yes you need to completely remove Office and re-install.

      How to completely remove Office for Mac 2011

      It’s possible if you revert to 14.2.3 or whatever version of Office was installed prior to 14.2.4, you would be able to open Outlook and export the data as .olm file and import that into 14.2.4 database.

      First rename the Microsoft Office 2011 folder in Applications to “Microsoft Office 2011 14.2.4” then restore the previous version of Office in Time Machine. Other wise you would need to do a re-install of Office and stop at the earlier version. If you can get an Identity to open rather than trying to upgrade, it’s best to export the data and import into a new Identity. Use rebuild as a last resort.

      After you have successfully exported your data, rename the earlier version of Office in Applications then remove the 14.2.4 from folder and use the newer version.

      Please read the directions in this article to help with the move: How to move your data to a new Identity

      However, my identity folder does not contain either the “Note” subfolder or the “Signature Attachments” subfolder.

      If you don’t have sigs or notes these folders would not exist.

      Always work off an original Identity. Once you start trying to rebuild, this can damage or delete data that’s needed for a complete restore.

  • Rob

    Thanks Diane.

    When I checked, I found error 255 and so I completely removed Office and re-installed it again. I installed SP2 14.2.0 then upgraded to 14.2.3. I then tried to open the identity but Outlook again terminated without displaying any error messages. (in the console, it was error 255 again).

    So I created a new identity and copied my data records to it (as described in the article on this page) and then attempted to rebuild. That also failed. However, unlike before the office reinstall, this time there was no error code next to the error message. It just said
    “Your database could not be rebuilt.”

    Shall I go ahead and upgrade to 14.2.4 and try again? Do you have any other suggestions?

    I have three other folders called “Arrangements”, “Rules” and “Tasks” in my data records. Do these need to be copied as well?


    • Just to be clear…

      You can now open Outlook without the error 255 and it doesn’t immediately quit.
      Your problem is opening your old Identity.
      If you create a new Identity, Outlook works as expected.

      I don’t think updating to 14.2.4 will fix this issue.

      What version was Outlook when the database failed? Was it a pre-SP2 14.2.x? If yes, reverting to the previous SP1 database utility might be needed.

      I have three other folders called “Arrangements”, “Rules” and “Tasks” in my data records. Do these need to be copied as well?

      Tasks contain data so I would copy those, but Rules can always be recreated. You could try recovering these in a separate new Identity to see if they recover without damaging any new recovered data. I would skip Arrangements. If it works, then export as .olm file to import into your new Identity.

      Try this on a copy of your Identity.

      1. Deleting the Database Headers in Data Records
      2. Delete the database file in the Identity
      3. Rebuild

      Make sure you are copying over the data records folders rather than dragging.

      It’s also possible the database is just too damaged to recover.

      Once you do get the Identity recovered, DO NOT trust it to be a stable Identity free from corruption. Export the data and start over in a new Identity

      How to move your data to a new Identity

      • Rob

        That is correct. Outlook works as expected when i open it with a new identity. Outlook terminates with error 255 only when my identity is set as the default. That WAS also the case before the uninstall/re-install.

        The database failed just as I upgraded from 14.2.3 to 14.2.4. It was working fine in 14.2.3

        I tried copying in “Tasks” as well, but that makes no difference. When I copy my data records to a new identity, i still get the error and the log screen looks as follows.

        Step 1 of 5: Scanning…
        Step 2 of 5: Verifying…
        Step 3 of 5: Copying records to new database…
        Step 4 of 5: Recovering Data…
        Your database could not be rebuilt.

        When I tried your other suggestion about deleting the database file and the “Database Headers” folder, I still get the same error, but I get it at the end of step 1 and the log screen looks as follows

        Step 1 of 5: Scanning…
        Your database could not be rebuilt.

        Any further suggestions?

        • Did you copy over the entire Data Records folder to the new Identity or just certain folders?

          Have you tried reverting to 14.2.3 to see if your Identity opens? Rename your current Microsoft Office folder in Applications. Use Restore option in Time Machine to bring back your previous version.

          If it opens in 14.2.3, then export all data as .olm file, switch back to 14.2.4 and import the .olm file into a new Identity.

          There was no database change from 14.2.3 to 14.2.4 so there was no reason for the database to fail due to the upgrade.

          It’s possible if I were working on your computer I could get this working but with Outlook there are no guarantees. I do charge for personal support. I would like to have the time to support everyone that asks, however there are just so many hours in the day. Offering free support for everyone is just not possible.

          You can view my rates here:

          • Rob

            I only copied certain folders to the new identity. In particular, the ones mentioned in at the top of this article. I also tried it with copying in “tasks” and with copying in “Arrangements” as well but that also failed to rebuild.

            I haven’t tried reverting to 14.2.3 since I have been away from home for almost two months and my latest time machine backup is dated the 25th of August. I will have access to this backup hopefully by tomorrow. My main concern is that my emails are deleted off of my mail server 10 days after they are downloaded into Outlook. So even if I revert to my latest working backup, that would still not contain most of my data from the last two months.

            My data records are 12.7 GB containing a total of about 107,000 files with about 56,000 files in “Messages” and 11,800 files in “Message Sources”. So, if I revert back to 25 August (assuming that this would be a successful restore) would I then need to “salvage” all my other messages with a later date as described in other posts on this blog?

            Regarding your invaluable support, I am more than happy to pay for your time or even make a donation to an account of your choice in appreciation for your help. I am willing to make that donation even if I manage to recover my data through this conversation without you having to take time out for personal support. I am also willing to pay for your charges of personal support where I would be willing to give you full temporary access to my computer but not willing at all to upload my data records.


          • You only need to revert the Microsoft Office folder in Applications to see if the older version would allow you to rebuild.

            I suggest you work off a copy when you try this option. Every time you rebuild or move/rebuild it can damage the files. I’ve even seen a duplicate Identity fail to open when the original opens. That makes no sense. One would think since you can see the files in Data Records you would be able to recover, but it has turned out to be much more complicated than recovering Entourage data that was hidden away.

            At this point, I feel like I’m guessing how to fix because I’m working blind. I’ll send an email to you with my contact info if you are unable to convert your data by reverting.

          • nabil chair

            need your supper for a fee, how do I get in touch with you, email? or..?
            same problem with outlook identities, backuped from time machine, but when I open it opens but empty!! everything i had in there before is not present.
            sure need help.

            I am in the UK, but can adapt to your time zone as needed.


          • I sent you an email with instructions to contact me. We’re 8 hrs time difference. I have several clients in London and we usually schedule around 6-7PM London time or later.

  • Iven Conjamalay

    Hi Diane,

    I’m having exactly the same issues as Rob, i’ve tried all the solutions which you provided over here, but the problem persists, could you provide me additional support for this!!?

  • Hi, just a quick thanks and mini-account of my experience. New HD courtesy of Apple’s Seagate recall for iMacs, and a bit of horror story as they reinstalled the wrong OS, which wreaked havoc on backup, then had to begin over.

    Anyway, I was left with one dangling problem – a big one, as my business has been running with Office over 10 years, and a year ago I converted 1000’s of PC-Office files (w/email, docs, etc.) to Appple. Thought I was done (with daemons, tho it is Halloween now – but enough spooks).

    I had many hours indoors during the storm to rebuild my (Lion) apps and data, and then left with Office/Mac popping up an error message nonstop of missing db. One day of rebuild attempts, referring often to your nicely-linked and detailed file directory step-by-steps. Bottom line: Apple (senior analysts and engineer) all deferred in the end to Microsoft, from whom I was disconnected in my transcontinental “support”. I read technical papers and support docs on both Apple and MS. And had a few screens open with your related articles. I used your general strategy and ultimately after a day of working on my own, ended up (again) creating a new identity, and then manually re-adding just the orignial folders you listed. I left a few odd ones out (“fold”) and ignored the few versions of “database” from the old, huge but corrupted/unusuable db.

    As I hoped/imagined, finally it rebuilt, new user, and with ancient messages/data I’d forgotten. All there. BUT – it was like 11GB. I read warnings (yours?) about >2Gig directories needing to be carved up, which might take a few years I was thinking. But… After the rebuild I ended up with 600+ “recovered folders”, numbered and also mostly following my old directory tree for email, so just a matter of exploring, renaming, and moving around 600+ directories and their contents. “How I spent my day”.

    I’m almost done, and have ridded my (new) HD of lots of old gunk, PLUS much better organized my 15 years of Office-related files, including email. (I never lost the docs.) I did lose signatures (no big deal) and filter rules, but since I’ve made new folder titles, that’s fine, and I’m now better set going forward, and will just add rules as new mail comes in. And oh yes, the attachments are all attached. And I checked just now – contacts are there.

    So bottom line, your list of key folders was very helpful, along with advice on ‘identity management’ and general considerations. I’m just really happy to finally have my computer back and Office for Mac finally back up and running, after a misplaced OS and intransigent MS/Apple/TimeCapsule recovery kept me glued to the screen 24/7 for 2 days (with a hurricane as soundtrack).

    Thank you, really what I’m writing to say. I kept your pages onscreen once I was sick and tired of reading support docs on Microsoft and Apple. It *can* be done, but for people with tons of docs and email being reconstituted after a “bad database” and “no rebuild for you’experience – it really takes some time both to get it to “take” and perhaps having to sort hundred folders now un-tree’d and renamed “recovered”. Whew. Done. Not so easy, tho!
    Your sharing of experience was helpful, much more so than the ‘geniuses’! 😉

    • Thanks for sharing your experiences. All this while a hurricane is blasting away.

      Going forward, I suggest you not only backup via Time Machine but you also clone your drive/Identity. It wouldn’t hurt to be double safe by creating a duplicate once a week. Then keep one per month. Keep only the last 3 months as a safe guard. Since Time Machine does not backup the database and requires you rebuild, if that fails you need a copy of your Identity with a database. That would be your clone. The extra duplicates would cover you just in case there is hidden corruption.

      Lastly, any messages under “On My Computer” is subject to loss. If you are using POP move to IMAP.

  • Axel

    Diane –

    My Outlook has joined the bandwagon and I have the same issue as Rob. How can we get in touch?

    Kind regards,


  • Matt Kita

    I got as far as Step 4 above. But where do I copy these folders to? I can’t find the folder containing my new “Identity” on my Mac. Please help!


    • Your Identities are stored in the Microsoft User Data folder in Documents.

      ~/Documents/Microsoft User Data/Office 2011 Identities/your identity

      Look for an email from me asking for more info.

  • E Willems

    I’ve a problem recovering my Outlook for Mac 2011. This is what I’ve been trying:
    – restored complete identity from time machine
    – when I start Outlook, it says « Your Office database index is missing and needs to be rebuilt. This is usually caused by restoring an identity with Time Machine. »
    – then I pushed « rebuild »
    – after step4, it says ” Your database could not be rebuilt. [-18000] »

    At one point, I succeeded restoring but all my ‘on my computer’ folders where in ‘recovered folders xyz’, in total about 4000…

    Could you pls let me know the conditions to get your personal help?

  • Rob


    There are two different ways you can recover your data. The first way is basically following Diane’s instructions at the very top of this page, however, with the following modification.

    Do NOT copy the folder “FOLDERS”, but copy “CATEGORIES” instead.

    This will result in you being able to recover all of your data, but you would lose all you folder names and hierarchical structure. (Eg. I had 10 folders at the top of my hierarchy, with loads of subfolders inside subfolders inside subfolders etc… In total the number of folders I have is 558). When my data was recovered in this manner, I had 558 folders at the top level all named “Recovered Folder 1”, “Recovered Folder 2”, “Recovered Folder 3”, etc… Obviously, it would be a nightmare to try and rebuild that hierarchical structure again. In fact, in my case, it would almost be impossible. If you don’t share my problem of having to recover the folders named and organised and sorted, and you just need your messages back, then this first solution would be easier for you.

    One thing to keep in mind though, before I start explaining the second recovery method, is that memory is the key to recovery. My database is 12.7GB and I had 120GB of free space on my hard drive, but that failed to recover. It even failed to rebuild a non-corrupted identity. And so I freed up some space and tried again with 200GB of free space on my hard drive, but that failed too. I freed up even more space and tried again with 310GB of free space on my hard drive, and that succeeded to build. (WIERD BUT VERY TRUE) I also did notice that during the rebuild, my computer was using about 6.8GB of RAM. So, I would recommend that you make sure you have at least 300GB of free space on your hard disk and at least 8GB of RAM installed. Otherwise, you would just be wasting your valuable time. By the way, these memory constraints apply to both of the recovery procedures; the one described above and the other one described below.

    If you wish to rescue your folder structure, read the steps below very carefully and try to follow them precisely and hopefully you will be able to recover your data.

    1. Make a duplicate copy of your data to work with and keep your original corrupted identity safe in case this method of recovery doesn’t work for you.
    2. Use the instructions at to completely remove all Microsoft Office from your system.
    3. Restart your computer.
    4. Install the original Office 2011 14.0.0 onto your computer, and make sure it is activated.
    5. Open a blank document in Microsoft Word, and allow it to fully load up. Then quit Word.
    6. Launch Microsoft Auto Update and upgrade Office to SP1 14.1.0. Make sure that you do not install any later updates than that.
    7. Open a blank document in Microsoft Word, and allow it to fully load up. Then quit Word.
    8. Manually download and intsall update 14.1.4 from
    9. Disconnect your computer from the Internet and do NOT reconnect it again until you have completed the recovery.
    10. Open the Microsoft Database Utility, and delete all the existing identities. There should only be one. Your corrupted identity should not appear in there. DO NOT DELETE IT if it is there (you must have done something wrong….start over).
    11. Now that there are no identities in the list, create a new blank identity. It will automatically be named “Identity 1”.
    12. Quit the database utility.
    13. In the duplicate of your corrupted identity (created in step 1), delete the database file. Then navigate to the “Data Records” folder and delete the “Database Headers” folder.
    14. Now copy the “Database Headers” folder from “/Documents/Microsoft User Data/Office 2011 Identities/Indentity 1/Data Records” and paste it inside the “Data Records” folder of the duplicate of your corrupted identity. What you have done now, is copy a clean “Database Headers” folder that has database headers in version 14.1.4. What you intend to do here, is trick the database utility v14.1.4 to think that your SP2 identity conforms to its own version and will then attempt to rebuild it.
    15. Delete “Identity 1” from the location mentioned in the previous step (you won’t need it anymore) and then move the duplicate of your corrupted identity in its place.
    16. Now launch the database utility, and you should only see that duplicate of your corrupted identity. Nothing else should be listed there. Now click Rebuild and keep your fingers crossed (that’s of course only if you have enough memory as explained earlier. Otherwise, it would just be a waste of your time because the rebuild will probable fail).
    17. You should receive a message saying that your database was rebuilt successfully. Now, quit the database utility.
    18. While you are still disconnected from the internet, start Microsoft Outlook. (and there you go, all your data back in front of your eyes….with all the folder structures maintained)……BUT HOLD ON, you’re not done yet.
    19. Follow steps 1,2,3, and 4 from
    20. Once you have quit Outlook in step 4 at that link in the previous step, start Microsoft AutoUpdate and install all available updates until you Office is updated to 14.2.4.
    21. Now go back to and skip step 5. Go to Step 6 and continue to the end of that document.
    22. You should now have your Outlook looking exactly as it did the day your identity got corrupted, hopefully with no data lost at all.


  • StevePazian posted these steps on the Microsoft Forum. You’ll note similarities with Rob’s steps for copying categories not folders. I have not tried either method yet myself but plan to do so soon and will get back with my results. I’m anxious to hear feedback from others that try these options.

    Here is how I learned to solve this problem caused by a SP2 auto-update:

    Make sure you are upgraded to Service Pack 2 (SP2) 14.2.1 – 14.2.2 (you can confirm this by opening Word and looking under about Word)
    Create a new blank Identity and remove the database (drag to trash)
    Quit Outlook.
    COPY these Data Records folders from the old Identity to the new blank Identity replacing the new identity folders. Do NOT replace the root Data Records folder. Only the sub-folders listed here.
    Categories (not folders)
    Mail Accounts
    Message Attachments
    Message Sources
    Signature Attachments
    Select to rebuild the new Identity in database utility; ignore any message that tells you that you need to rebuild your database while the database utility is working.
    Open Outlook and your data should be back.

    Most resources neglect to tell you to drag the new identity database to trash before you copy over the old identity records. Also, they may tell you to copy over the old identity folders records instead of the categories records, but don’t as that is likely to cause a problem; it did for me.

    I lost my Outlook folder labels I gave them (the folders were labeled as recovered folder 1 – xxx), so plan to redo them. Good luck!

    • Eric Carrier

      I have had similar issues with the SP3 upgrade to Outlook for Mac 2011. Just wanted to let you all know that after screwing around for the better half of a valuable Sunday, Diane’s instructions above WORKED!

      Thanks so much.

  • Sue

    I have I hope a simple question! I am using Office 2008 and had to have my hard drive replaced. Everything was fine except for the Entourage emails. After a long and stressful day I managed to rebuild the identity and have got everything back but due to my many attempts I have a lot of identities – very large files sitting on my computer – best not to ask. Can I delete them all except the new working identity without losing anything?

    • Yes, you can delete the other Identities with some caution. Since the Identity name doesn’t show up in the Entourage window, I would put these Identities in the trash, log out/in under the Apple in the Menu bar then open Entourage and verify that you have saved the right Identity.

      Also go into the Entourage Spotlight cache folder and delete all Identities you see there. Entourage will create new cache files for you new Identity.

      “YOUR USER FOLDER/Library/Caches/Metadata/Microsoft/Entourage”

      Lastly, I never trust a rebuilt Identity to be clear of corruption. Move into a new Identity to be sure. See the steps here. They were written for Outlook but the concepts are the same. Entourage export/imports as .rge where Outlook uses .olm.

      Delete your current Identity and leave only the new Identity you created.

  • Michael

    Hoping you can help….!!

    My problem was similar to the above – I would click to open Outlook, it would appear to be opening and then terminate with no notification after about 5 seconds.

    I followed the instructions and rebuilt the current data base (by pressing ‘Alt’ when clicking on the Outlook icon).

    Data base was successfully rebuilt and Outlook opened. Emails were being received as per normal, however as soon as I tried to respond to an email or write a new email a message would appear indicating database would need to be re-built. I would proceed to have database re-built and the same would occur when Outlook was reopened (emails would download however I would be asked to rebuild as soon as I responded or tried to type a new email).

    Any suggestions?

    • Open the Console in Applications/Utilities. In the top filter (String Matching), enter Outlook. Do you see error 255? Post one each of the different errors you see. There can be hundreds of the same error. 🙂

      If you do have the error 255, you will need to do a complete re-install of Microsoft Office 2011. We’ll get that if necessary.

      As long as Outlook opens, your best option is to move to a new Identity rather than try rebuilding. The more you rebuild, the more likely you are making matters worse. I always like to work off the original Identity BEFORE the rebuild process started.

      The steps in How to move your data to a new Identity explain how to delete your IMAP and Exchange accounts first. You are left with “On My Computer” data only. Export this as .olm file. Be sure you get “Done” at the end. Other wise there could be corruption that needs to be addressed before you go forward.

      Create a new Identity and import the .olm file. Add back IMAP and Exchange accounts.

  • Pierre

    Hi all,

    Just for your information I’ve just finished the rebuild of my crashed Outlook (v.14.2.5) database (8.9 GB) following the tutorial above (Rob’s first method copying Categories instead of Folders). When I started the process I just had 19 GB of free space on a MacBook 2.4 Ghz Core Duo with 2 GB of RAM running Mac OS X 10.8.2 and everything worked fine (just that I’ve lost all my folders). So I’m not sure that having so much disk space/RAM available is really an issue. At least not for me.

    Thanks for these great tutorial pages Diane.


    • If your rebuild fails, then free space would most likely be the one thing that would allow a rebuild to work. While not all users must have it to rebuild, many others will require it for a successful rebuild.

      Since you lost your folders you can try the method described here: Outlook rebuild results in folders named Recovered
      This method has worked for several different issues with rebuilding.

      Look for a private message from me.

  • Ashish

    Diane thanks for such an information outlook on the Outlook 2011. I was able to rebuild with new identity with solutions provided above.

  • Steve

    I have a MB pro running 10.6.8 using Outlook 2011. I did a rebuild and many emails are missing, most that were in subfolders. Is there a process to perform a more detailed rebuild to get all the data back. I read the above but there are alot of different things being addressed so want to make sure I follow the right instructions.

    During the rebuild the HD filled up so I moved off iphoto library and now have space. I also have a used but new 2011 MB Pro that I can load office 2011 onto and transfer the file there to work on if need be.

    Database file is 62 GB.
    Sadly last full back up was Oct 24.



    • Hi Steve, When you say you have space, how much free space?

      I would recommend you follow the steps listed in this article. Outlook rebuild results in folders named Recovered

      The setup is the hard part but this method has been very successful for all types of damaged Identities.

      Since you have another computer, you could install Office and stop at 14.1.0 to do the recovery, but while it might recover with less than 300 GB free the more free space you have the better your chances for recovery.

      The database file being 62 GB is an anomaly. If you do a Get Info on the Data Records folder (the original before the rebuild) what size is Data Records? The process doesn’t even use the database file.

  • Jeroen van der Schaaf

    ERROR -18000

    Dear all –

    After struggling for quite some time to recover Outlook and get stuff back up and running again, I found something that miraculously worked, with only 1 minor downside:

    I worked from backups – always do so!!!

    After creating a new identy, I kept getting error message -18000. Insipred by a post, I decided to remove the contents (not the folder, just the contents) of ‘FOLDERS’. Then, I again tried to rebuild the database, and it completed with no error.

    Downside: all maps I created to store email are now named “herstelde map 1”, “herstelde map 2” etc. I don’t care tbh, I got all my emails back

    (strangely enough, my OS’es Spotlight had been reindexing during the existence of this problem and was suddenly done as well at the same time.)

    • When you mention ‘FOLDERS’, do you mean the folder in Data Records named “Folders” or all folders in Data Records.

      How much free space on drive when you tried to rebuild and failed? The -18000 have been rebuilding successfully on my drive with 500 GB free.

      Thanks for sharing your solution. While losing folder names is not optimum it’s better than having no messages.

      • Jeroen van der Schaaf

        hi Diane –

        Sorry – I meant the folder named ‘FOLDERS’. Initially, I copied all, and then rebuilding failed (-18000). Then I removed ‘FOLDERS’, tried again, and it completed and recovered all my email.

        Maybe putting back the removed folder ‘FOLDERS’ after completing the rebuilding would work; after all, the database was built succesfully, and it’s just a matter of reading out data. I am and was very reluctant to try this, because of all the work already put in it. Someone working with small files might be willing to try; my Outlook data was close to 9 GB, so trying things was already (too) time consuming.

        I completed this with 247GB of free space.

        However – when starting up Outlook, I still got the message this morning that Outlook needed to update identities and messages. So I am still facing a reinstall of Outlook a/o Office I’m afraid. But at least I made several backups now.

        • Usually when we see the needs updating and it starts the progress window where you see two bars updating is a one time process. I’m afraid that re-installing Office is not going to fix tis.

          Export your data as .olm file then import into a new Identity. This should fix the updating problem. If you have IMAP and/or Exchange, see details here How to move your data to a new Identity

          Let me know if this helps.

          • Jeroen van der Schaaf

            I decided to do something I usually never do: I called Microsoft. Tech support acknowledges this is a known issue. That’s something :).

            Someone from MS will call me back tomorrow, and guide me through 2 possible solutions for the ‘Updating Identities & Messages’ issue. I was warned there’s no guaranteed fix, but ‘we’re just gonna try’. I’ll have backups made. I guess exporting and importing into a new identity will be one of their solutions.

            Since it will be an Office/Mac specialist I have on the phone, I will bring up the former issue (missing emails and the complicated road to recover) as well, and explain my own workaround in detail. It will hopefully help them a bit to come to a solid fix for this.

            I’ll take notes if possible, and report back here.

            One very strange thing: the support I will receive is free of charge because I use POP-email……. IMAP / Exchange and they would have needed my creditcard as this is then considered business support. I told him I use my email 100% business-wise only, and it’s still free. Strange policy!

    • Renato Alves

      Dears Diane and specially Jeroen

      I write from Brazil and you save my life. After 3 hours doing this procedure and always enconter error -18000, abve 4:00 am and fall asleeping, I decide read more comments and find a SIMPLE AS THAT BE comment post by Jeroen:

      “delete de “folders” folder contents.”

      Than, without choices, I do this. Simple, obviously and bulleye shot. The recovery system pass ok and all messages recovered, signatures, contacts, accounts, filters, rules…

      Just a simple problem is the “folder 1, 2, 3″order, but for me, not problem, because I organize my folders by subjects and this easy to rename.

      Please, Jeroen, send me a personal e-mail with your contacs, that I want to send you a gift, not for payment, but to recognise your help for a unknow friend over the sea.

      Thank you so much.


  • Restoration procedure (create new identity and copy data folders into the data Records folder, trash the new database so the repair utility creates a new one) worked great…EXCEPT I lost my rules and blocked senders – any helpful suggestions to restore from backup?

    When I used the database utility to do the repair, I had not added in the mailing list rules or signatures files, nor did I have the fold, Rules,Signatures or UID’s folder included. However, I have my signatures working, everything else seems OK just missing my rules and blocked senders list.

    Any help appreciated. Thanks so much for this resource. Best resource for these problems – I used to have lots of headaches withentourage until I switched to Outlook in the 2011 bundle. I’d been avoiding upgrades forever. Should have read about any warnings – at least I was backed up in 3 places before I began the upgrade to 14.2.5 😉


    • The ability to export Rules has been a long standing request. Using screen shots is the best option. It’s possible if you copied over the Rules folder to a new Identity then rebuilt, it would recover the rules. 1) You could then import your messages as .olm file into the Identity with rules etc. 2) Working off a copy of your new Identity you could try this same import, but the rebuild process would be more difficult because of the size of the messages.

      Not sure where they even store the blocked senders list to recover. If the Identity opens you should be able to copy from the blocked senders window. If the Identity does not open, your pretty much out of luck. In the future, I would assign blocked senders a category and add them to the Address Book to give you a way to export and save this data.

      The link to the restore option Outlook rebuild results in folders named Recovered is the best option to recover everything. The setup process for it is pretty time consuming and requires the hardware to accommodate it as well.

      If the above fails…..Send me your Identity without the 3 messages folder, I could try rebuilding for you to see if that works. You could then import your messages as .olm file into the Identity with rules etc. Do this off a copy. I’ll send you a private reply so you can contact me directly.

  • Hi Diane: Got the rules working fine after rebuilding my identity. Made sure before I started to back up my recovery like you suggested in another post. Thanks for all your help and the great info on this site!


  • Oliver Macdonald

    Took me a while; rebuilding the identity using the ‘folders’ folder from a backup wouldn’t work but using the ‘categories’ folder did. All my old folders seem to appear as ‘Recovered folders’ so just need sorting and renaming. I also included the ‘Exchange Accounts’ folder which got my exchange account settings back.

    Many thanks

  • Also took me a while, the key was the process is really:
    1. Create the new identity with the MS database utility.
    2. Copy the items listed in the top of the post.
    3. Rebuild the database.

    If you do that it worked like a charm.

  • amy

    i am seriously near tears. after going through this entire process last week and starting from scratch, and rebuilding my entire outlook all over again (hours, and hours) , just as i was about to complete a weekly backup it crashed again. i have a .olm file but would really like to try once again for the recovery of this week’s work.

    i tried the steps for rebuild by copying my identify and the folders (didn’t try categories yet, i suppose that’s next) but now i see a 255 error in console. does that mean i need to reinstall?

    is this program that unstable that i should consider not using it any longer even if i can rebuild?
    i am usually pretty resilient but this has got me….

    • I prefer the option in the article “Outlook rebuild results in folders named Recovered” described in red at the beginning of the article to recover data. The setup is the only difficult part. Every Identity I’ve rebuilt for clients using this method was successful.

      You do need to work with an Identity that has not been rebuilt for best results. Every time you rebuild the data is further damaged. Basics for a Successful Rebuild

      Rebuilding is the first step. Using an Identity that has been rebuilt is just waiting for it to crash again. Export all your data and import into a new Identity after rebuilding. How to move your data to a new Identity

      This does not mean you will not have further issues. I would only use Outlook with IMAP or Exchange account and keep no mail under “On My Computer” folder unless they are backed up as .olm or .mbox files.

      The error 255 code is one of the worst. It can mean you need to remove all bits manually of Office and re-install or it could mean serious issues with your Identity. If you open Outlook in a new Identity, do you see this error. If no, try adding your IMAP and/or Exchange. Do you see if now? If yes, one items could be corrupted trying to sync to the server.

      If all this fails, do this same test in a new User. Testing in a new User will quickly tell you if the problem is system wide or if it’s your User’s folder that contains the problem. For help visit:

      Use new User to test for problems

      All this is more than most users can manage or endure. I’ve seen a lot of users give up on Outlook and move to Mail. It’s not as pretty but it’s stable.

  • amy

    thank you for the quick reply. so, if i attempted to rebuild using the database utility as a first step, does it mean that i shouldn’t bother trying with the identity on my hard drive? interestingly, my outlook just magically opened in i don’t even know what identity since i’ve been moving folders around. would it be better to use a time capsule backup?

    also, my hard drive is only 250 GB to begin with, so do i even have enough memory? somehow today i went form 99GB free to 54, so i’m trying to track down what’s taking up all the space. i do have a 500 GB seagate i can use for external rebuilding but it isn’t empty.

    also, why would this reoccur so soon after the last debacle? i redownloaded all my emails from the server last week into a new identity and have been trying to delete things to get the overall size down but i hadn’t made that much progress. there’s something like 65K messages in there… i actually went as far as reinstalling Lion last week, so Office should be a fresh install. so disappointed in the lack of robustness.

    thanks so much – i may enlist you to help me via fee for service soon. seems to me to be well worth it.

  • amy

    also, if i created a time capsule earlier today, would that be a better bet for recovery?

    • Yes, the Time Machine Identity would be best if it’s not just a copy of the Identity that you have been trying to rebuild.

      You can use OmniDiskSweeper (free) to find large files. Most likely your multiple Identities are part of the issue.

      You should be able to tell by what’s selected as default in Database Utility to know what Identity is open.

      The free space you have might work. I just know from experience the more free space the better the odds of recovery. Using 14.1.0 to rebuild when 14.2x or newer will fail. See steps to do this in here: Outlook rebuild results in folders named Recovered

  • amy

    thanks again. i wound up giving up and redownloading all my email because the time capsule didn’t work and i don’t have earlier versions of Outlook as far as i know. i was a pc person until August and while Windows has its problems, Outlook for PC is much more robust and pst files offer a lot more flexibility for importing/exporting/opening/closing. Not experienced with restoring earlier software versions on mac either.

    i have no idea when/how i’ll get through all the thousands of messages to clean them up but at least i’m functional with what’s incoming. i went with IMAP for my gmail but my other account is comcast and as far as i can tell only offers POP3.

    is there a link you recommend that explains how best to organize the folders with imap? you had cautioned against using an ‘on my computer’ folder’ but i now see that i have one where i didn’t before,.

    • Outlook for Mac is a v1 product where Outlook for Windows is a mature product. They don’t have a lot in common other than the name and the ribbon.

      Comcast is only POP. See this link to be sure you setup Gmail correctly. Connect Outlook for Mac 2011 to Gmail’s IMAP service It explains about creating folders. It’s not advised to let the All Mail folder sync. If you were using Gmail as IMAP before it should sync the same folders.

      If you are ever interested in learning how to recover from Time Machine, it might be worth contacting me for help.

  • amy

    p.s thanks again.

  • Sam

    Hi Dianne, would you clarify something please? I need to migrate emails from Outlook for Mac v14.3.2 to Apple Mail v4.6 but I can’t export to an OLM file and my Outlook database looks to have corruption, so it’s asking me to rebuild the db. I’ve studied your excellent blog articles and posts here and the recommendation is to try other things before rebuilding – have I got that right? I currently use a POP account so all mail is On the Mac. Using OS X 10.6.8.

    My specific issues are:
    * Outlook won’t export emails to OLM file – it asks me to Rebuild the database (but exporting contacts to OLM is fine)
    * Some folders that used to have emails now don’t have any emails – totally empty, especially the older folders.
    * I can’t empty “deleted items” folder (has 5000 items) – asks to Rebuild db
    * I have a lot of data – Data Records Folder is 17GB! Database is 270MB.
    * Time machine does NOT copy the Outlook database file – but “duplicate” the folder does make a copy of the database file

    Note that the Emailchemy tool won’t help as it does requires an OLM file but their new version will not – see below.

    So could you clarify a few things about the process please?

    1. To make a copy of the Outlook files, I’m using “Duplicate” command which does copy the database file too. Do I need the whole Office 2011 identities folder or just the Main Identity folder?
    2. To move to a new identity(before Rebuilding), is this using the method of copying the contents of Data Records folder and setting it as default identity (as in article “How to recover your data when rebuilding…”)?
    3. Should I then try to rebuild or should I first prune the large folders over 2GB and try exporting?
    4. If export to OLM file still doesn’t work, do you (or anyone) know a way to export emails from Outlook to MBOX format? Apart from dragging each folder to the desktop.

    Note: Emailchemy told me today that “The current version of Emailchemy does require an OLM file. Then next version, version 12, will have the ability to convert the Outlook data natively. Version 12 is in beta testing now.”

    The good news is that I’m moving to cloud-based email (with IMAP!) but need to get my emails over so would be very grateful for your help on the above please….Thanks

    • When I recover Identities for clients, I use the Time Machine copy of the Identity without the database file. I use the method described here. Outlook rebuild results in folders named Recovered

      You only need an Identity folder, not the entire Office 2011 Identities folder.

      You do need to prune the folders over 2GB first.

      If you cannot export as .olm file, the only way to get .mbox files is to drag each individual folder. That includes subfolders.

      Why not add the IMAP account to Outlook and simply upload your messages to the new account?

      Hope this helps!

  • Sam

    Thanks very much for clearing those things, very helpful. I found out that adding an IMAP account to upload from Outlook won’t work as Google Apps (my new account) has an IMAP bandwidth limit for uploads – only 500MB per day, after which it locks out your account. But a nice idea… any more where that came from!
    (for those interested, here’s the IMAP limits for Google Apps:

    So any solution will have to extract data from Outlook for Mac and then use a 3rd party tool that doesn’t use IMAP to upload to Google Apps (then I can use IMAP account down to Apple Mail – apparently that doesn’t use up the limits).

    Has anyone used the “Google Email Uploader for Mac” tool? If I can get data out to Apple Mail via .mbox files, then Google Email Uploader for Mac can upload email from Apple Mail to a Google Apps mailbox. I did not get good results in a small test but will try that again. Has anyone else used it – would be helpful to hear your experience.

    Any other ideas very much appreciated please – for migrating from Outlook for Mac to Google Apps (with Apple Mail client). Thanks

  • Sam

    I will buy Emailchemy – thanks. Just taking several backups of my data! I will try and move to new identity as you describe, but if something were to go wrong during a rebuild, I understand (from Microsoft mac forum) that to restore Outlook for Mac 2011, you simply get rid of the partially rebuilt identity and rename the “Backed-up” one to make sure it has the default name as the original. Is that correct? You can tell I’m nervous…

  • You don’t have to rename, you can just select that Identity to open in the Database Utility. However, if you are going to try and rebuild, it’s safer to work off a backup than one that was created during the rebuild process.

  • Ian Paull

    Hello Diane

    I have ongoing issues with outlook for mac 2011 14.3.1. my osx is 10.8.3
    Like an idiot i managed to move my documents folder (inc microsoft user data) the other day and hence I lost it all. Managed to restore off time machine and got all my mail and folders back (great!) however, since then 2 issues have occurred. 1) My contacts list has duplicated. i’m hoping this is a simple fix of deleting the dupes somewhere in the id folder but i dont know how? 2) despite several attempts at reindexing with spotlight it will only find old contacts in my list, anything new doesnt show up?? again, most frustrating…I hope you can point me in the right direction?



  • Frank

    Hi Diane,

    My girlfriend’s Mac had Outlook problems. Your recipe enabled me to rebuild the database. But I did have to refrain from copying the Folders folder into the virgin new Identity or the Database Utility would not successfully build the database. This of course led to many many ‘recovered’ folders (586, to be exact). Bummer 🙁

    Then I thought: apparently somewhere within the Folders folder there must be the source of the corruption. What would happen if I included _part_ of the Folders contents to the virgin new Identity before rebuilding. A quick test proved that this approach was feasible – after including the 0K subfolder I could still build the database.

    Then I spent the rest of the day gradually including more and more of the Folders subfolders (each time starting with a virgin Identity) and rebuilding. My Folders folder contained subfolders named 0K to 72K. On each iteration I included 5 more of these. After including the block from 40K – 44K, the utility would no longer build. Leaving this block out, but continuing with 45K-49K et cetera, did give me successful builds again. Up to and including the last subfolder, 72K.

    Knowing the rough location of the corruption, I drilled down some more. In the end, I found out that I could successfully build the database, including folder names, if I only left out the 41K subfolder. After starting Outlook, I found out that I had only 16 ‘recovered’ folders. These, of course, were easy to rename and move back to the correct place in the folder hierarchy.

    You might want to include my approach to your web page. It takes a couple of hours, but much reduces the renaming phase of the process.

    Thanks for your web site with all the helpful information!



  • Sam

    Hi Diane
    I want to say a huge thank you for helping me with rebuilding my database. It was important data gathered over many years and you helped me do it in a safe way. Your vast experience & knowledge, and very quick responses were much appreciated. And you are a rare IT person who speaks in simple English. I’m glad I engaged your services and would do so again if I needed to.
    Best wishes