vs2015/2013 – Cannot see unit tests in Test Explorer window

If have some unitests in Visual Studio 2015 or 2013 but you cannot see them in your “Test Explorer window”

If you look in your output window, (under “Show output from:” > “test)

An exception was thrown while initializing part “Microsoft.VisualStudio.TestWindow.UI.TestWindowToolWindowControl”.

The solution is just to delete the VS2013/VS2015 cache folder, located either in

%LOCALAPPDATA%\Microsoft\VisualStudio\12.0\ComponentModelCache

For VS2013, or

%LOCALAPPDATA%\Microsoft\VisualStudio\14.0\ComponentModelCache

For VS2015