title: A project with an Output Type of Class Library cannot be started directly.
body: <p>When I try to run my application, I ge the the following error;
  <img src="https://i.stack.imgur.com/URSmm.png" alt="enter image description here"></p>
  
  <p>I know this issue has come up many times, and the usual answer is to right click on the appropriate project and make it the start up project.</p>
  
  <p>Well I have done that and this does not fix it.</p>
  
  <p>My application is an MVC application, so the start up project should be a class library.</p>
  
  <p>It was working fine until I tried to upgrade it to MVC5.</p>
  
  <p>I am working on VS 2012.</p>
  
  <p>I am wondering if the problem was caused by unloading and reloading the csproj file which I edited as part of the upgrade?</p>