On a server that is running Microsoft Forefront Unified Access Gateway 2010, the W3wp.exe process may randomly stop and cause all sessions to disconnect. When this occurs, you receive the following error message:
A process serving application pool 'DefaultAppPool' suffered a fatal communication error with the Windows Process Activation Service. The process id was 'process_id'. The data field contains the error number.
Additionally, an error message is logged in the Application event section of the Windows Logs event log that resembles the following:
This problem occurs because of an access violation (Exception code: 0xc0000005) in the worker process. This occurs because of an invalid pointer.
To resolve this problem, install Service Pack 4 for Microsoft Forefront Unified Access Gateway 2010.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
See the terminology Microsoft uses to describe software updates.