How to reproduce:
1. Open the attached “IN-122461.zip“ project
2. Enter Play Mode
3. Select the “Inspector” GameObject
4. Observe the Console

Expected result: No error is thrown
Actual result: NullReferenceException Error is thrown

Reproducible with: 2023.1.0a1, 6000.0.61f1, 6000.2.11f1, 6000.3.0b9, 6000.4.0a4

Reproducible on: Windows 11 Pro (24H2)
Not reproducible on: No other environments tested

Workarounds:
- Have no .asmdef files in your Assets/ directory
- Create a .asmdef file in Assets/Editor that is only applied to “Editor”