How to reproduce:
1. Import the attached "Oak_Hero_Field" SpeedTree Asset
2. Drag the imported Asset into the Scene
3. Select the SpeedTree Asset in the Hierarchy
4. Observe the Inspector
Expected results: There is no Asset Preview window because it should be available only when selecting the Asset in the Project window
Actual results: There is an Asset Preview window but it is empty
Reproducible with: 2021.3.44f1, 2022.3.38f1, 6000.0.21f1
Reproducible on: Windows 11 Pro
Not reproducible on: No other environment tested