1. What happened
Selected a skeletal mesh FBX importer preset asset and Unity crashed.

2. How we can reproduce it using the example you attached
Open the project, click on the preset in the Project window. Crash!

Here's a potentially helpful snippet from the Editor.log file:

Dereferencing NULL PPtr!
UnityEditor.ModelImporter:get_transformPaths()
UnityEditor.ModelImporterRigEditor:OnEnable() (at C:\buildslave\unity\build\Editor\Mono\ImportSettings\ModelImporterRigEditor.cs:130)
UnityEditor.AssetImporterTabbedEditor:OnEnable() (at C:\buildslave\unity\build\Editor\Mono\Inspector\TabbedEditor.cs:83)
UnityEditor.ModelImporterEditor:OnEnable() (at C:\buildslave\unity\build\Editor\Mono\ImportSettings\ModelImporterEditor.cs:17)
UnityEditor.Editor:CreateEditorWithContext(Object[], Object, Type)
UnityEditor.Editor:CreateEditor(Object[], Type) (at C:\buildslave\unity\build\artifacts\generated\bindings_old\common\Editor\EditorBindings.gen.cs:143)
UnityEditor.Editor:CreateEditor(Object[]) (at C:\buildslave\unity\build\artifacts\generated\bindings_old\common\Editor\EditorBindings.gen.cs:138)
UnityEditor.Presets.PresetEditor:GenerateInternalEditor() (at C:\buildslave\unity\build\Modules\PresetsEditor\PresetEditor.cs:162)
UnityEditor.Presets.PresetEditor:OnEnable() (at C:\buildslave\unity\build\Modules\PresetsEditor\PresetEditor.cs:57)

[c:\buildslave\unity\build\runtime\baseclasses\PPtr.h line 255]
(Filename: C:/buildslave/unity/build/Editor/Mono/ImportSettings/ModelImporterRigEditor.cs Line: 130)