Can't debug MSpec Tests any more - DisconnectedContext

Suddenly while writing code and tests with MSpec and debugging them I started getting an Error, which makes it impossible to debug my tests any more.

The tests run but if I hit debug I get an Error named "DisconnectedContext".

The messages says that the Managed Debug Assistant found a problem in "C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO 14.0\COMMON7\IDE\COMMONEXTENSIONS\MICROSOFT\TESTWINDOW\te.processhost.managed.exe"

I also get the error in a new project with an empty test that does nothing.

In another solution I'm getting a FileNotFoundException for "C:\USERS\ME\APPDATA\LOCAL\MICROSOFT\VISUALSTUDIO\14.0\EXTENSIONS\WGPFTPGA.WNV\Machine.VSTestAdapter.resources.dll" when doing the exact same thing.

What do you think? Is my studio suddenly damaged or is it a settings problem? I already tryed reinstalling the MSpec testadapter.