After you install Rollup 1 for Microsoft Forefront Unified Access Gateway 2010 Service Pack 4, client HTTP connections to the Unified Access Gateway redirect trunk may intermittently receive one of the following error messages:
Error message 1:
You cannot access this site due to an internal error.
Error message 2:
You have attempted to access a restricted URL.
This problem occurs because Rollup 1 for Forefront Unified Access Gateway 2010 Service Pack 4 changed how the NLSessionC cookie for the HTTP redirect trunk is applied. An initial client connection to this trunk is successfully redirected to HTTPS. However, any successive client HTTP connections in the same session fail because of the missing NLSessionC cookie.
This problem is fixed in Rollup 2for Forefront Unified Access Gateway 2010 Service Pack 4.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.