I have the same problem as James Frost (Post Offline Address Book not downloading (From CCR Cluster)), but I still get get a 1021 error when I restart MSExchangeFDS.exe with RU5 applied. It can't access the OAB generation directory using the CCR cluster name. This is a new migration, that is a 2 node Exchange 2007 CCR installed on Windows Server 2008. I have two CAS/Hub servers installed on Windows Server 2008. The fix for this is supposed to be KB954197, which was included in RU5. I have installed all the rollups, including RU6 on each server. The ClientAccess\OAB directory was empty on the CAS servers, so I manually copied them over and gave domain users "read" rights, and I can download the OAB in Outlook 2007. However, I still can't access the ExchangeOAB directory on the Active Node in the CCR using the Cluster Name (\\ClusterName\ExchangeOAB), but can using the Node name (\\NodeA\ExchangeOAB). I could use the Robocopy method and update the directory once in a while, but would rather get this working on it's own.Does anyone have some ideas on what to do next?

Issue description: CAS server cant copy OAB from OAB share on the CCR nodes by using CMS name Troubleshooting: 1. Please verify that RU5 has been applied on both nodes (Please see my second post in this thread) 2. Please apply Hotfix 955733 to correct the wrong status with cluster file share 3. Please enable the diagnostic logging EventLogLevel Set-EventLogLevel -identity "MSExchangeSA\OAL Generator" -level Expert 4. Please remove GUID folder from path C:\Program files\Microsoft\Exchange Server\ExchangeOAB, and restart the Microsoft Exchange File Distribution and System Attendant service on the active node 5. Make sure that this directory and share has Read permission for the "Exchange Servers" group 6. Check the ExchangeOAB folder on the MBX and CAS server, the event in the application log