Track cannot be loaded

I tried opening my project in Unity 2021.2 (a11 to be precise) and now all custom timeline tracks show “Track cannot be loaded” warning. They have been working fine since 2019.2.

I re-imported the timeline asset and I got this warning. Re-importing the related scripts gave similar warnings.

Closing Unity, deleting Library, and then starting Unity again makes the tracks work for a while. I can enter the play mode a few times before the tracks suddenly cannot be loaded again. Only deleting Library folder seems to fix it.

Is there some upgrade step that needs to be done? Or is this simply a bug?

Hi @Havokki ,

This looks like an instance of this known issue: Unity Issue Tracker - "generated inconsistent result" warning when reimporting single asset

A fix for it will be available in a13. Please try that version when it comes out and see if it resolves the issue. If things are still going wrong, we’d appreciate a bug report with a reproducible so we can investigate.

I tried with a13, and it seems to work a bit better.

Now all tracks are unloadable when I start Unity, but re-importing related scripts fixes it, and they seem to work even when I start the game or make code changes. However, restarting Unity makes them unloadable again.

I’ll try to repro this in a smaller project that I can share and report a bug at some point this week.

Thanks, that would be very helpful!