I'm upgrading my existing development environment from VS2008, .Net 3.5 to VS2012, .Net 4.5.
Had enough problems that I finally created a drop-dead-simple VS2012 C# library project (.Net 4.5) with one class and one test case.
Tests run fine if I run them in the standard NUnit Test Console, but in TestMatrix, invoked from within VS2012, I get this big popup with text in it:
"An error occurred while loading attribute 'IServiceBehavior' on type 'Server'. Please see InnerException for more details. System.InvalidOperationException: An error occurred... (chunks deleted to save space) ... System.IO.FileNotFoundException: Could not load file or assembly 'System.ServiceModel, Version=220.127.116.11, Culture=neutral, PublicKeyToken=b77a5c561934e089'
The dialog appears several times. During that time the Debug Shim is visible in the Task Manager. Once I've dismissed all the dialogs, the Debug Shim disappears.
I'm running the latest version of TestMatrix 3.1.12211.