title: TargetInvocationException in VS 2013 Ultimate xUnit
body: <p>After install VS 2013 Ultimate not work xunit tests in VS 2012 and VS 2013. I have exception in debug: "An unhandled exception of type 'System.Reflection.TargetInvocationException' occurred in mscorlib.dll". Inner exeption: "Exception has been thrown by the target of an invocation". How decided this problem?</p>