Work around for bug

Work around for #42982

src/EditorFeatures/TestUtilities/TestExtensionErrorHandler.cs

@@ -36,6 +36,13 @@ public void HandleError(object sender, Exception exception)
                 return;
             }
 
+            // Work around for https://github.com/dotnet/roslyn/issues/42982
+            if (exception is NullReferenceException &&
+                exception.StackTrace.Contains("Microsoft.CodeAnalysis.Completion.Providers.AbstractEmbeddedLanguageCompletionProvider.GetLanguageProviders"))
+            {
+                return;
+            }
+
             // Work around for https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1091056
             if (exception is InvalidOperationException &&
                 exception.StackTrace.Contains("Microsoft.VisualStudio.Language.Intellisense.AsyncCompletion.Implementation.CompletionTelemetryHost"))