I encountered this error message on all Direct Access clients a few days ago (in the advanced diagnostics log):

I encountered a Computer Certificate on a Domain Controller which was about to expire soon, and needed to replace it.

Recently I encountered a problem with authenticating via my ADFS Server because of an internal PKI CRL that was not reachable (resource provided by a third party, users in my organization).

I had tried to configure single sign-on for a third party web page with MS ADFS 3.

I recently ran into an issue after upgrading a virtual machine from Windows Server 2003 SP2 32-bit to Windows Server 2008 SP2 32-bit.

I was working on a PowerShell script for some mundane management task in Exchange 2010 SP3, and was met with a crash in the Integrated Scripting Environment when trying to run the script: After some trial and error, I gave up and resorted to a Google search, and found the answer in some forum post on technet.