title: Parameter name Type ISession cannot be resolved when debugging in Visual Studio 2015
body: <p>Started getting a new error when starting a debugging session in VS2015.  It's an ASP.NET MCV project that also exposes a WCF service (don't know if that's relevant).</p>
  
  <p>The debugging session takes ages to start up and then I get a message box saying:</p>
  
  <blockquote>
    <p>Specified argument was out of the range of valid values.</p>
    
    <p>Parameter name: Type ISession cannot be resolved. Interfaces of
    abstract classes should be registered first.</p>
  </blockquote>
  
  <p>After that the debugger works as expected.</p>
  
  <p>If I do the same thing from VS 2013 then it takes a long time to load but I get a message saying:</p>
  
  <blockquote>
    <p>Loading symbols for WebActivatorEx.dll from:
    d:\Code\GitHub\WebActivator\WebActivator\obj\Debug</p>
  </blockquote>
  
  <p>This is strange because I haven't knowingly installed WebActivator and my D: drive is a DVD that I haven't opened since I got the PC.</p>
  
  <p>Yesterday I installed OpenCover, but it didn't work so I removed it.</p>
  
  <p>Anyone out there who might have an idea of what's going on???</p>
  
  <p>Thanks</p>