When you try to start the Microsoft Exchange Service Host service on a Microsoft Exchange Server 2010 server, the service crashes and the following event is logged in the Application log:
Log Name: Application Source: MSExchange Common Date: Date Event ID: 4999 Task Category: General Level: Error Keywords: Classic User: N/A Computer: Computer Description: Watson report about to be sent for process id: Process ID, with parameters: E12, Build Type, Version Number, M.Exchange.ServiceHost, M.Exchange.SACLWatcherServicelet, M.E.S.S.Servicelet.VerifyAndRecoverSaclRight, System.NullReferenceException, XXXX, Version Number. ErrorReportingEnabled: False
Additionally, the following event is logged in the System log:
Log Name: System Source: Service Control Manager Date: Date Event ID: 7034 Task Category: None Level: Error Keywords: Classic User: N/A Computer: Computer Description: The Microsoft Exchange Service Host service terminated unexpectedly. It has done this X time(s).
This issue occurs because the Exchange Service Host service encounters a System.NullReferenceException exception when the service tries to access the system access control list (SACL) during the startup process.
To resolve this issue, install the following update rollup:
2746164 Description of Update Rollup 6 for Exchange Server 2010 Service Pack 2
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.