How to reproduce:
1. Open the attached "AddressablesGUIErrors.zip" project
2. Go to "Window -> Asset Management -> Addressables -> Groups"
3. Observe the Console
Actual result: Multiple errors related to GUI and TreeView are thrown in the Console
Expected result: No errors are thrown in the Console
Reproducible with: 1.21.21 (2023.3.0a2), 3.1.0 (6000.5.6f1)
Reproducible on: Windows 11
Not reproducible on: No other environments tested