If you see these errors in your Event Logs, then most likely Outlook clients aren’t downloading the Offline Address Book. To fix this, you will need to edit the registry on your Exchange server.

Event ID 9360

Event ID: 9360
Category: OAL Generator
Source: MSExchangeSA
Type: Error
Message: OALGen encountered an error while generating the changes.oab file for version 2 and 3 differential downloads of address list “\Global Address List”. The offline address list has not been updated so clients will not be able to download the current set of changes. Check other logged events to find the cause of this error. If the cause of the problem was intentional or cannot be resolved OALGen can be forced to post a full offline address list by creating the DWORD registry key “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeSA\Parameters\OAL post full if diff fails” and setting it to 1 on this server. When OALGen next generates the offline address list clients will perform a full OAB download. After that time the registry key should be removed to prevent further full downloads.

Event ID 9331

Event ID: 9331
Category: OAL Generator
Source: MSExchangeSA
Type: Error
Message: OALGen encountered error 8004011b (internal ID 5020114) accessing the public folder store while generating the offline address list for address list ‘\Global Address List’. – Default Offline Address List

Solution:
1. Click Start, click Run, type regedit in the Open box, and then click OK.
2. Locate and then right-click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeSA\Parameters
3. Point to New, and then click DWORD Value.
4. Type OAL post full if diff fails to name the new value.
5. Right-click OAL post full if diff fails, and then click Modify.
6. In the Value data box, type 1, and then click OK.
7. Exit Registry Editor.

It after this and still doesn’t work, then you might want to dismount the Public Folder Store and try recreating the Offline Address List again.