I was at a customer today, where they have just installed a new Exchange 2010 SP2 CAS server with the UM role also. However the “MSExchange Unified Messaging” Service would not start.
A quick look in the application event log showed the below entries:
The UM worker process (UMWorkerProcess.exe) couldn’t start. More information: A file couldn’t be converted for playback over the telephone: An error occurred in the Audio Compression Manager: The operation completed successfully
The Unified Messaging worker process has terminated. The state of the UM worker process is “Init”.
The Microsoft Exchange Unified Messaging service was unable to start. More information: “Microsoft.Exchange.UM.UMService.UMServiceException: The UM worker process encountered a fatal error during startup.
at Microsoft.Exchange.UM.UMService.UMService.OnStartInternal(String args)”
The Unified Messaging server shut down process umservice (PID=5300) because a fatal error occurred.
The solution to the problem was to install “Desktop Experience” on the server, and after a restart of the server, the UM service started as it should.