title: Decompiled Sources only show "throw null" for every .NET Framework class
body: <p>I have</p>
  <ul>
  <li>installed Visual Studio Community 2019, version 16.3.3 (including &quot;ASP.NET and Web development&quot; and &quot;.NET Core cross-platform development&quot;)</li>
  <li>and have checked &quot;Enable Navigation to decompiled Sources&quot;,</li>
  <li>and created a new ASP.NET Core Web Application (.NET Core 3.0.0)</li>
  </ul>
  <p>but when I then look at e.g. the decompiled source for any referenced class in the .NET framework e.g. <code>System.Console</code> or for <code>Microsoft.AspNetCore.Builder</code> (or almost any other type), all I can see for every method's body is throw null (I showed an extract below)</p>
  <p>I have read <a href="https://stackoverflow.com/questions/51400507/decompiling-net-assemblies-only-shows-throw-null">this</a> question (update: and the <a href="https://stackoverflow.com/questions/9701135/reference-assemblies-folder-and-different-assemblies-with-the-same-version/9702071#9702071">answer</a> to the question it was a duplicate to), but there only one class had this problem (because it was added in an incremental update). For me, this problem applies to every class in the .NET framework. What am I doing wrong? Is this expected behaviour and I should use something like dotPeek?
  Can I use a symbols server instead of decompiled sources?
  (Forgive my ignorance, I'm really new to C#... and the .NET world)</p>
  <pre><code>region Assembly System.Console, Version=4.1.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
  // C:\Program Files\dotnet\packs\Microsoft.NETCore.App.Ref\3.0.0\ref\netcoreapp3.0\System.Console.dll
  // Decompiled with ICSharpCode.Decompiler 4.0.0.4521
  #endregion
  
  using System.IO;
  using System.Text;
  namespace System
  {
  
  // Summary:
  // .... 
      public static ConsoleColor BackgroundColor
      {
          get
          {
              throw null;
          }
          set
          {
          }
      }
  
      //
      // Summary:
      //...
      public static int BufferHeight
      {
          get
          {
              throw null;
          }
          set
          {
          }
      }
      ...
  </code></pre>