Issue
When launching a test from MTM, either manual or automated, it would get the message, MTM does not launch Test Runner and fails to do anything. The following error message was added to the Event Log after failure:
<Provider Name="VSTTExecution" />
<Data>(mtm.exe, PID 16168, Thread 1) Exception: System.IO.FileNotFoundException
Message: Could not load file or assembly 'Microsoft.VisualStudio.TestTools.UITest.WindowsStoreUtility, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.
Troubleshooting
We tried running it from another computer to isolate the Visual Studio Ultimate as the issue. It worked on another computer with Visual Studio Ultimate 2013 Update 3. The failing computer had Visual Studio Ultimate Update 2.
Resolution/Workaround
Root cause was not determined. Installing Update 3 fixed it.