In a Microsoft Forefront Threat Management Gateway 2010 (TMG) environment, the Firewall service (Wspsrv.exe) in Forefront TMG may intermittently crash when it processes client web proxy requests. When this problem occurs, you may find that the following event is logged in the System log:
Event ID: 14176
The Firewall service stopped because an application filter module drive:\Program Files\Microsoft Forefront Threat Management Gateway\MSPHLPR.dll generated an exception code C0000005 in address 0000000072B7E7C2 when function CompleteAsyncIO was called. To resolve this error, remove recently installed application filters and restart the service.
To resolve this problem, install the hotfix package that is described in the following Microsoft Knowledge Base article:
2689195 Rollup 2 for Forefront Threat Management Gateway (TMG) 2010 Service Pack 2
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates