title: no source available to run tests in Visual Studio 2017
body: <p>I'm having trouble debugging a project. When I double click on the tests to open them, it says "no source available" and I can not also debug or run a specific one. I can only run them all by the tool or by git bash using dotnet test.</p>
  
  <p>Any idea what that might be? These problems started when we migrated to ASP.NET Core.</p>
  
  <p>Project is with net461.</p>
  
  <p>Thanks,</p>