How to reproduce:
1. Open any project in 2019.2.0a12 or above and install Visual Studio Editor package
2. Write any Unity related script in any file (for example something containing GameObjects or Transforms)
-- Observe the console errors

Reproduced with: 2019.3.0a4 with package version 1.0.2 and 1.0.10
Couldn't reproduce on any 2019.2 version with any package version.

Note: Different kind of errors in 2019.3.0a1.

Errors:
NullReferenceException: Object reference not set to an instance of an object
UnityEditor.Experimental.AssetImporters.AssetImporterEditor.InternalSetTargets (UnityEngine.Object[] t) (at C:/buildslave/unity/build/Modules/AssetPipelineEditor/ImportSettings/AssetImporterEditor.cs:122)
UnityEditor.Editor.OnForceReloadInspector () (at C:/buildslave/unity/build/Editor/Mono/Inspector/Editor.cs:603)