An error occurs when you try to replicate conference directory data from Windows Management Instrumentation (WMI) to the back-end server. This issue occurs when you deploy Microsoft Lync Server 2010 and Microsoft Office Communications Server 2007 R2 in the same forest. Additionally, the following event is logged in the Application logs:
An unexpected error occurred when trying to replicate conference directory data from WMI to the back-end. This will be retried, but if this error continues to occur, the Office Communications Server service will need to be restarted.
Error code: 0xC3EE7950 Cause: Possible issues with the back-end or WMI service. Resolution: Ensure that the back-end is functioning correctly and that the WMI service is healthy.