title: Cannot add assemblies to .Net Core application in Visual Studio 2019
body: <p>When I try to add a missing assembly to my project (for unit testing specifically) I noticed that the Assemblies tab is missing in the "Add Reference" dialog , see:</p>
  
  <p><a href="https://i.stack.imgur.com/hl803.png" rel="noreferrer"><img src="https://i.stack.imgur.com/hl803.png" alt="enter image description here"></a></p>
  
  <p>Is this a bug or a expected behavior? If it's expected how we are supposed to add the missing assemblies.</p>
  
  <p>Note that I already tried through Nuget package manager and still didn't work.</p>