title: The directory containing the assemblies for the Visual Studio Test Runner is not valid
body: <p>We have upgraded our TFS installation from 2012 to 2013. When running our builds they will fail with the following error if unit tests are enabled:</p>
  
  <pre><code>TF900547: The directory containing the assemblies for the Visual Studio Test Runner 
            is not valid ''
  </code></pre>
  
  <p>The build process template or build definitions has not been changed after the upgrade. The upgrade process did not change them. <strong>Where can I provide the path to the Visual Studio Test Runner and where is it located on disk?</strong></p>
  
  <p>I do not know if "Visual Studio Test Runner" is a new option for 2013 or if this setting was also used before, when we were using TFS 2012.</p>
  
  <p>We use Visual Studio Professional 2012 on the build server. </p>