Explain how to solve "It was not possible to find any compatible fram… (#38937)

* Explain how to solve "It was not possible to find any compatible framework version."

Occurs when DOTNET_ROOT is pointing to another install such as 5.0.23, but the dotnet-dump expects a more recent release such as 6 or 7.

* Update docs/core/diagnostics/faq-dumps.yml

Co-authored-by: Genevieve Warren <[email protected]>

---------

Co-authored-by: David Pine <[email protected]>
Co-authored-by: Genevieve Warren <[email protected]>

Author: 3 people

docs/core/diagnostics/faq-dumps.yml

@@ -33,3 +33,7 @@ sections:
           * [Debug Linux dumps](debug-linux-dumps.md) 
           * [Debug a deadlock in a .NET app](debug-deadlock.md) 
        
+      - question: |
+           How can I solve "It was not possible to find any compatible framework version"
+        answer: |
+            On Linux, the `DOTNET_ROOT` environment variable must point to the correct folder when set. When it points to another .NET version, `dotnet-dump` always produces this error. When the `DOTNET_ROOT` environment variable isn't set, a different error is produced ("You must install .NET to run this application").