[1.16.5] <world_folder>/umc/chunks.raw breaks if resource packs change after initial world generation.

[Stealthx3]

I've identified an issue with what I'm pretty sure is UMC on 1.16.5
(UniversalModCore-1.16.5-forge-1.1.4-b3d4f6a.jar - ImmersiveRailroading-1.16.5-forge-1.9.1-e49acbb.jar)

Whenever the resource packs are updated after initial world generation the <world_folder>/umc/chunks.raw file breaks causing the affected server to hang at "preloading spawn" and leaves it unable to fully start. I can provide logs but it doesn't seem to be identifiable from them at least as far as I can tell.

After we deleted the chunks.raw file and caused it to regen the issue subsided.

Unknown if this is caused only when an already existing pack gets updated or if any change to the resource packs for IR triggers the issue.

[cam72cam]

Can you provide the log files / broken chunks.raw?

[Stealthx3]

Yes, it also seems that the issue is NOT in fact completely fixed after doing said change, as nobody can log in even though the server is fully started -_-

Logs: Logs.gz
Chunks.raw: chunks.zip

The issue is also repeatable as things
work when I restore the server to a backup prior to the update
and then the issue happens again if I try to update.

No other changes have been made in said update, only resource packs.

[cam72cam]

So chunks.raw documents what chunks should be loaded. Between that and the users logging in loading chunks, there's probably a piece of rolling stock that was removed in a pack that is being loaded automatically.

What packs are you updating? Do you know if any stock was removed?