title: Cannot add any shared projects to solution in VS2019
body: <p>I am using VS2019 16.0.0 Preview 4.4</p>
  
  <p>If I create a new C# WPF project, then right click on the solution and click "Add new project". Create a C# class project and add it.</p>
  
  <p>Now if I right click on references on the main startup project and click "add reference". Under shared projects the list is empty and I cannot add anything.</p>
  
  <p>If I open an existing project with shared projects that was created in VS2017, all references to the shared project show up as intellisense errors with red squiggles. If I run the solution it compiles and runs fine.</p>
  
  <p>It seems the GUI component cannot see any referenced projects, however at the MSBUILD level everything works correctly.</p>
  
  <p>I have tried deleting the .VS folder with no luck.</p>
  
  <p>Why do shared projects not work in VS2019 ?</p>
  
  <p>Jere is a screenshot of a VS2017 project which opens, compiles and runs fine, but all the shared project references show up as red intellisense errors.</p>
  
  <p>I have raised a question on the developer community forums with no response for over a week
  <a href="https://developercommunity.visualstudio.com/content/problem/490528/shared-projects-is-empty-and-all-referenced-projec.html" rel="nofollow noreferrer">https://developercommunity.visualstudio.com/content/problem/490528/shared-projects-is-empty-and-all-referenced-projec.html</a></p>
  
  <p><a href="https://i.stack.imgur.com/aUvz6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aUvz6.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/RuK6I.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RuK6I.png" alt="enter image description here"></a></p>