You get an error message with Microsoft Test Manager 2010:
Automatic connection to the following team project failed: <project_name> on server <tfs server>. Click refresh to display all currently available team projects, then connect to the project that you want to use.
- This error message displays everytime you are trying to connect to the MTM 2010 though you are able to connect to TFS successfully from the VS 2010.
- The issue doesnt goes off after installing the hotfix and deleting the cache.
For me the solution of adding the values in the mtm.exe.config worked and I was able to connect to TFS from MTM:
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" />
</startup>
Do note that the changes need to be made to the mtm.exe.config file under the root configuration node which is available(by default) at the path "C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\mtm.exe.config" and not to the mcm.config in the cache folder