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Exchange 2010 blank OAB

Users might get a blank OAB/GAL in Outlook with exchange 2010. It took me a week to figure this out since there was no traces found on the internet.

Error message:

Exception Exception type: System.NullReferenceException

Exception message: Object reference not set to an instance of an object.

This is how I resolved it:

1. Install support tools and open ADSIEDIT

2. Expand the Configuration container and navigate to this location–Exchange–Organization name

4. Go to the properties of organization name

5. Double click on the attribute: MSExchResourceAddressLists

6. Here, we are looking for an entry which has deleted items in it. This would be an address list entry which was not deleted properly. In my case, it was:

CN=Printer mailboxes\0BAFAB:3a62e7b2-32c2-513a-c2c3-2bbd316324fc,CN=Deleted Objects,CN=Configuration,DC=Ratish,DC=Main,DC=com

7. Delete this entry, restart your IIS and confirm.


18 Responses to “Exchange 2010 blank OAB”

  1. Kim Kirchhoff Says:

    You just saved me for many hours !!!!
    after migrating from Exchange 2007 to Exchange 2010

    Thanks – worked

  2. R Blunden Says:

    Excellent, spot on fix for my Exchange 2010 system.
    I tidied up the Address Lists in 2003 as they didn’t want to migrate to 2010 and deleted one in the process of cleanup (on purpose). OWA in 2010 GAL then failed with your exact error.
    This fixed it!
    Many Many Thanks.

  3. Ratish Sekhar Says:

    Im glad it worked…. Cheers !!!

  4. Ronald Says:

    Amazing. Google showed me your website. Do you know what caused this issue?

  5. Russell Says:

    Great fix. Do I have to make any further change or just leave it like the way it is? Thanks again.

  6. Rebecca Says:

    You are a true life saver… I wonder why microsoft dont write a kb for this issue….

  7. Peter Says:

    Thank you so much guys. This worked for me.

  8. Tom G Says:

    This never solved my issue. Im still troubleshooting.

  9. Anderw Says:

    MSExchangeguru – you guys are the best ! This fixed my issue in 5 minutes and I coulnt thank enough! Awesome work


  10. Manuel Says:

    Great fix. this worked for me. Thanks a lot

  11. Aldo Says:

    Great fix. this worked for me. Thanks a lot

  12. Ebo Says:

    Simply awesome solution… worked like a charm !!!

  13. Travis Says:

    Had this issue after an Exchange 2003 to 2010 Migration. Tried this fix and it worked.

  14. Shane Says:


  15. David Says:

    Very smart fix. Thanks a lot

  16. Alex Ma Says:

    Thank you very much!

  17. chris Says:


    This fixed my issue.

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