“GUI Error” and “NullReferenceException” errors are thrown in the Console when building a project with a custom Light Type selected and Light Explorer window open

Steps to reproduce:
1. Create new Unity project using Universal 2D Template
2. Import provided custom light script to the project “MyCustomLightProvider.cs”
3. Select Global Light 2D in Hierarchy window
4. Make sure Light Type is set to “My Custom Light”
5. Open Light Explorer window and dock it next to Game tab
6. Build and run the project (Command+B)
7. Observe the Console window

Actual results: Errors “GUI Error: Invalid GUILayout state in LightingExplorerWindow view. Verify that all layout Begin/End calls match” and “NullReferenceException” are thrown in the Console window when trying to build and run the project

Expected results: No errors are thrown in the Console window when trying to build and run the project

Reproducible with versions: 6000.5.0b6, 6000.6.0a4

Can’t test with versions: 6000.0.73f1, 6000.3.14f1. 6000.4.4f1 (No such feature, script errors)

Tested on (OS): macOS Silicon Tahoe 26.4.1