title: Visual Studio does not recognize a referenced assembly?
body: <p>Opened an old project from years ago. Build fails because Visual Studio (2019) does not recognize an assembly that is clearly there - specifically, Autofac.</p>
  <ol>
  <li><p>You can see it in project references (not marked as missing)
  <a href="https://i.stack.imgur.com/s5soU.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/s5soU.jpg" alt="Project References" /></a></p>
  </li>
  <li><p>You can see it in the Object Browser, listing all the types referenced in the code</p>
  </li>
  </ol>
  <p><a href="https://i.stack.imgur.com/SXw3O.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SXw3O.jpg" alt="In Object Browser" /></a></p>
  <ol start="3">
  <li>But in code, none of the types show up, gone AWOL.</li>
  </ol>
  <p><a href="https://i.stack.imgur.com/ro5Dr.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ro5Dr.jpg" alt="In code" /></a></p>
  <p>What is going on here? Intellisense doesn't even pick up types
  (Tried cleaning, rebuilding, re-importing packages)</p>