Symptoms
On a server that is running Microsoft Forefront Threat Management Gateway 2010, you create a web access rule by using the Web Access Policy Wizard or the New Access Rule Wizard. However, when the rule's properties are configured to use a custom schedule, such as Work Hours, the Firewall service crashes.
Resolution
To resolve this problem, apply the service pack that is described in the following Microsoft Knowledge Base article:
2555840 Description of Service Pack 2 for Microsoft Forefront Threat Management Gateway 2010
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
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
