The Firewall service (Wspsrv.exe) may crash intermittently after you apply ISA Server 2006 Service Pack 1

After you apply Microsoft Internet Security and Acceleration (ISA) Server 2006 Service Pack 1 (SP1), the Firewall service (Wspsrv.exe) may crash intermittently.

Additionally, the following events are logged in the Application log:

<Error>
Event Type: Error
Event Source: Microsoft ISA Server Control
Event Category: None
Event ID: 14079
Date: date
Time: time
User: N/A
Computer: servername
Description: Due to an unexpected error, the service fwsrv stopped responding to all requests. Stop the service or the corresponding process if it does not respond, and then start it again. Check for related error messages.
</Error>

<Error>
Event Type: Error
Event Source: Microsoft ISA Server 2006
Event Category: None
Event ID: 1000
Date: date
Time: time
User: N/A
Computer: servername
Description: Faulting application wspsrv.exe, version 5.0.5723.493, stamp 48623ea3, faulting module w3filter.dll, version 5.0.5723.493, stamp 48623e85, debug? 0, fault address 0x00039e9a.
</Error>

<Error>
Event Type: Error
Event Source: Microsoft Firewall
Event Category: None
Event ID: 14057
Date: date
Time: time
User: N/A
Computer: servername
Description: The Firewall service stopped because an application filter module drive:\Program Files\Microsoft ISA Server\w3filter.dll generated an exception code C0000005 in address 64729E9A when function CompleteAsyncIO was called. To resolve this error, remove recently installed application filters and restart the service.
</Error>

This problem occurs when the caching functionality is enabled and when there are content type-based rules.

This problem occurs because of an issue in ISA Server 2006 SP1. After you apply ISA Server 2006 SP1, ISA Server may incorrectly handle a response that is served from the cache when content type-based rules are being used. This issue can cause the Firewall service to crash.

To resolve this problem, apply hotfix 956269.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

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: