OALGen encountered an error while generating the changes.oab file for differential downloads. Clients will not be able to incrementally update to the new version of the OAL. This is normal if this is the first time this OAL has been generated. There is no previous version for clients to start with. Check other logged events to see if this is a serious error. (\Global Address List)
All the other rebuild the offline address book events in the event viewer seem fine.
One last thing to consider is that some sent emails are failing with a email from the Exchange Server stating that the email can not be delivered and the reason is unknown.
I'm feeling that there is something wrong with the Globel Address List.
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