PS5 build with FSM causes app to fail on startup

[diccon]

We've are making a PS5 port and our game features a lot of Playmaker FSMs which have worked well so far, but suddenly the build crashes immediately on startup with this error:

The file '/app0/Media/level0' is corrupted! Remove it and launch unity again!

Through a process of elimination and stripping the build right down to an empty scene containing a single FSM it is my conclusion that the FSM is causing the problem, because when I remove the FSM and build the empty scene runs ok.
I have asked Unity support but since it is an asset problem they won't suggest anything other than to delete the Library folder (which I did and it did not help).

Can you think of anything that might help with this?  I am using Playmaker 1.9.5.

Thanks!

[Alex Chouls]

Are you using version control? Can you diff the file and see what changed?

I haven't seen this error before, but online some people suggest creating a new scene and transferring your GameObjects to it.

[bevis0405]

You've already reduced it to an empty scene + FSM and found the FSM is the trigger. That's valuable and rules out most general build issues.

[diccon]

I have tried making a new scene, and even if it only contains a single FSM that does nothing the build corruption occurs.  I believe it is some kind of error in the Unity build process for PS5 but since it is caused by middleware they only offer vague advice:

I'm not sure how the corrupted error could occur, that it is "corrupted" is a very generalized way of saying, it could not be parsed. It could have bad references, it could have a damaged header, the compression might not make sense. Given the issue seems linked to the presence of 3rd party classes, I expect there is a feature being used in the serialization that is not available or does not function cleanly on all platforms, and it is resulting in unexpected behaviour.

The fact that it used to work and then suddenly stopped working, and that I have other PS5 projects with FSMs that work, suggests that it might be something to do with the build cache, however deleting the Library folder did not work.  I don't know if you are aware of anything in the FSM serialization that gets cached and could go wrong like this?