Hi Exchange 2010 SP1. When I try to show Offline Address Books, I receive an error: [PS] C:\Windows\system32>Get-OfflineAddressBook WARNING: An unexpected error has occurred and a Watson dump is being generated: An item with the same key has already been added. An item with the same key has already been added. + CategoryInfo : NotSpecified: (:) [Get-OfflineAddressBook], ArgumentException + FullyQualifiedErrorId : System.ArgumentException,Microsoft.Exchange.Management.SystemConfigurationTasks.GetOffli neAddressBook The same happens with new-offlineaddressbook. In the event log on all Exchange servers error appears: MSExchange Common id 4999: Watson report about to be sent for process id: 2644, with parameters: E12, c-RTL-AMD64, 14.01.0285.000, AutoDisc, M.E.Data.Directory, M.E.D.D.S.OfflineAddressBookMapiProperty.ReadSchema, System.ArgumentException, b8a2, 14.01.0289.001. ErrorReportingEnabled: False

If you look in eventviewer do you get any errors there??/jonas

Check the AD for errors. Duplicate accounts for example. Did you manipulated any AD data before the error occured? ADSIEDIT? Restore of DC? Be sure to have Rollup 3v3 for MS EX 2010 SP1 installed on all affected servers. Bart

Is the OAB working at all aside from this error? Can users download the oab and is the oab updating? If you try to run this command from another Exchange server does it produce the same error?James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Hi, Please navigate Offline Address Book tab within Mailbox in Organization Configuration and check whether there is any OAB folder. Meanwhile, I suggest you restart System Attendant service and check the result. If the issue persists, please type the following cmdlet to increase the Event Log level and monitor the Event log. If there is any OAB Event error, please post detail information here. Set-EventLogLevel -Identity "MSExchangeSA\OAL Generator" -Level High Thanks. Novak Wu TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Servers was restarted many times. Diagnostic logging have been already set and no other errors appears. Offline Address Book is not updating on Outlook clients. There are no other errors. seems to be a new bug in SP1 :)

I don’t think it’s a bug in SP1 since there is no problem in my lab which is also upgraded to SP1. At this stage, I suggest you temporarily turn off firewall and antivirus program on the server and check the result again. If the issue persists, please type tasklist command in Command Console and check which System Process used the PID 2644. Thanks. Novak Wu TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

There was .NET 4 installed on the servers. Seems like uninstalling it solved the problem.

Thank you for sharing the solution here. It’s useful to other forum users if they have the same problem in future. Regards, Novak Wu TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.