title: Startup Project keeps reverting to IIS Express for debugging
body: <p>In my solution I basically have two projects, the one I'm coding on, and the startup project, <code>Startup.csproj</code>. I have <code>Startup.csproj</code> configured to use <code>Local IIS</code> for debugging, and I normally just attach to the worker process to debug.</p>
  
  <p>However, at random intervals, the <code>Startup.csproj</code> defaults back to IIS Express for debugging. It does not show as a change in the <code>Startup.csproj</code> project file, and sometimes even still shows <code>Local IIS</code> but fails with a "Cannot list contents of directory" error.</p>
  
  <p>I'm running VS 2017 v15.9.15. What could be causing this annoying little phenomenon?</p>