Reproduction steps:
1. Open the attached “BugRepro” project
2. Open the “Assets/Scenes/SampleScene” Scene
3. Open the Font Asset Creator window (Window > TextMeshPro > FontAssetCreator)
4. Observe the Console window
Expected result: No errors are logged in the Console
Actual result: Multiple “GUI Error” and “NullReferenceException” errors are logged in the Console
Reproducible with: 2023.2.15f1, 6000.0.0b12
Couldn't test with: 2021.3.36f1, 2022.3.22f1 (multiple “NullReferenceException” errors after importing TextMeshPro package)
Reproducible on: Windows 11
Not reproducible on: No other environment tested
Note: Sometimes the Font Asset Creator window needs to be closed and reopened multiple times for the errors to appear