A. A recent Microsoft update to the .NET Framework is causing problems for some vSphere clients. Microsoft has more information about its 980773 update. Only vSphere clients prior to vSphere Update 1 are experiencing this problem.
When attempting to launch the vSphere Client, if you're affected, you'll see an error message similar to the following:
Error parsing the server "<servername>" "clients.xml" file.
The type initializer for VirtualInfrastructure.Utils.HttpWebRequestProxy' threw an exception.
The resolution for this fix is to update your vSphere client to Update 1 (build 208111) or Update 2 (258672) from VMware’s download site.
This problem affects vSphere clients on Windows 7, Windows Server 2008, Windows Vista, Windows Server 2003, and Windows XP.