Exchange 2010: Fix problems with downloading the offline address book

From time to time there are problems when downloading the offline address book, the causes are often different and have different error messages. The following instructions describe how to "start again" with a fresh offline address book (OAB), which solves most problems.

First stop the "Address book" and "File distribution" services

Now delete the defective OAB

Next, delete the files of the old address book from all CAS servers, the files are located under "C:\Program Files\Microsoft\Exchange Server\V14\ClientAccess\OAB". In this example, the entire folder "92721951-0e98-40cb-a12e-6c04115d9fc9" can be deleted.

Now delete the directory under "C:\Program Files\Microsoft\Exchange Server\V14\ExchangeOAB" on the server that generated the OAB, i.e. a mailbox server

Next, recreate the virtual directory (OAB)

A new offline address book can now be created:

The virtual directory OAB is assigned to the new OAB again

As soon as the OAB has been created, it can be generated (Get-OfflineAddressBook | Update-OfflineAddressBook)

Now reuse the application pool "MSExchangeAutodiscoverAppPool" in the IIS Manager on the CAS servers

Finally, restart the "Address book" and "File distribution" services.

After restarting Outlook, you should now be able to download the new address book again.