How to reproduce:
1. Open the user’s attached “AnimationPlayerStandalone.zip” project
2. Select any GameObject and add a “Test Script“ Component
3. Observe the Console window

Expected result: No errors
Actual result: “ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection” error appears

Reproducible with: 2021.3.34f1, 2022.3.17f1, 2023.2.4f1, 2023.3.0b1

Reproduced on: macOS 13.6.3 (Intel)
Not reproducible on: No other environment tested

Notes:
- not reproducible if enabling “Show Foldout Header” in UI Builder
- if changing Inspector mode to “Debug” and setting the number of elements and changing back to “Normal” Inspector mode, then the number of elements will be one less than the set value