title: Unity Container - ResolutionFailedException when removing covariance
body: <p>I have an a unity registration that works just fine with the out covariance, but once I remove it, I get the error</p>
  
  <blockquote>
    <p>"ClassName": "Microsoft.Practices.Unity.ResolutionFailedException",
    "Message": "Resolution of the dependency failed, type = \"REDACTED.IChatTranscriptBc<code>1[REDACTED]\", name = \"REDACTED\".\r\nException occurred while: Calling constructor Microsoft.Practices.Unity.InterceptionExtension.PolicyInjectionBehavior(Microsoft.Practices.Unity.InterceptionExtension.CurrentInterceptionRequest interceptionRequest, Microsoft.Practices.Unity.InterceptionExtension.InjectionPolicy[] policies, Microsoft.Practices.Unity.IUnityContainer container).\r\nException is: ArgumentException - Interface not found.\r\n-----------------------------------------------\r\nAt the time of the exception, the container was:\r\n\r\n  Resolving REDACTED.ChatTranscriptBc,REDACTED (mapped from REDACTED.IChatTranscriptBc</code>1[REDACTED], REDACTED)\r\n    Resolving Microsoft.Practices.Unity.InterceptionExtension.PolicyInjectionBehavior,(none)\r\n    Calling constructor Microsoft.Practices.Unity.InterceptionExtension.PolicyInjectionBehavior(Microsoft.Practices.Unity.InterceptionExtension.CurrentInterceptionRequest interceptionRequest, Microsoft.Practices.Unity.InterceptionExtension.InjectionPolicy[] policies, Microsoft.Practices.Unity.IUnityContainer container)\r\n"</p>
  </blockquote>
  
  <p>My interface when it works:</p>
  
  <pre><code>public interface IChatTranscriptBc&lt;out TTranscript&gt;
      where TTranscript : Transcript
  </code></pre>
  
  <p>My interface when it breaks</p>
  
  <pre><code>public interface IChatTranscriptBc&lt;TTranscript&gt;
      where TTranscript : Transcript
  </code></pre>
  
  <p>Literally, the only change is my removal of "out."  I've rebuilt all my libraries, restarted my computer, everything.  Any idea why the removal of the covariance breaks unity?</p>