Upgrading from 4.12 to 4.16 causes sequences to 'freeze'

I’m trying to upgrade our project from 4.12 to 4.16 and there are some really weird things happening with our sequences.

The strangest thing is that some of them just won’t play at all. They look fine in the sequence editor but when playing in the game they get stuck on the first frame of the sequence and just ‘freeze’.

I found that creating a new sequence and copy/pasting all the keys to there works but we have over 100 sequences in our game and can’t do that for all of them!

There must be something new in 4.16 causing this? I can’t seem to find anyone with the same problem though!

I fixed it…

I had an AI character in the sequence and found that if I disabled that track then it would play fine. So I put a new AI character in the level, assigned that to the track, and then switched it back to the original one and deleted the new one. Weirdest bug ever haha.