How to reproduce:
1. Open the attached "IN-141388_TestBuiltinTimeline.zip" project
2. Open the “New Timelime” in Assets folder
3. Right-click in the left pane and add any track.
4. Observe the Console window
Actual result: “Timeline Track type appears to be invalid ” warnings are logged
Expected result: No warnings are logged
Reproducible with: 1.8.9 (6000.3.0a4), 1.8.12 (6000.5.0b8, 6000.6.0a4)
Not reproducible with: 1.8.8 (6000.3.0a4)
Fixed in: 6.6.0 (6000.6.0a5)
Reproducible on: Windows 11
Not reproducible on: No other environments tested