title: The project type is not supported by this installation
body: <p>Whenever I try to open a project <code>(csproj)</code> that's downloaded from the internet, most of the times, I get the </p>
  
  <blockquote>
    <p>"The project type is not supported by this installation"</p>
  </blockquote>
  
  <p>It appears that my Visual Studio installation is not corrupted (I can pretty much do everything with it other than open these csproj files)</p>
  
  <p>What may be causing this?</p>