title: Issue with running Unit Test in Visual Studio 2012
body: <p>I am getting the following error while building unit-test.</p>
  
  <pre><code>Error: "IUnitTestStorage.Open should be called before operation can continue."
  </code></pre>
  
  <p>I have never got this error before and all was working fine before this moment. </p>
  
  <p>I have tried deleting all bin and obj files and rebuillding, it didn't help. Moreover, when I created new unit-test project (with no code of mine) and it gives the same error.</p>
  
  <p>Closing all Visual Studio instances and starting them back didn't help as well.</p>
  
  <p>I am using Visual Studio 2012 Premium Update 4.</p>