More information.

I found the answer. The reason for the non-playback or AVFoundation error was that too many AVVMutableCompositionTracks were used. I used 30 video assets, and whenever I got tracks from asset, I always used addMutableTrack(withMediaType mediaType:, preferredTrackID:) -> AVMutableCompositionTrack?. Which means more than 30 compositionTracks are created. We have confirmed that these generated tracks cause performance degradation and playback errors. Assets with essentially non-overlapping globalTimeRange could solve this problem by using the same compositionTrack. I hope it helps people who have the same phenomenon as me.

To add more information, it was verified using AVVideoComposition's 'determineValidity' and there was no problem in the results or callbacks.

I'm experiencing a similar phenomenon, and I'm trying to solve it. Have you corrected this phenomenon?

I'm having the same problem. xcode : Version 13.4.1 (13F100) mac : 12.3