We have migrated to UE5.7 3 weeks ago. Our Gameplay gamemode hasn’t changed since. however today we changed the DefaultPawnClass (which uses the same character class as BP parent, but the child has no changes).
Right after we did that change tried to test it on Steam build and the DefaultPawnClass is null (all other variables are fine on the GM). in editor it works fine
We recently had a similar issue with a custom class that recently included a TSubclassOf<AActor> with UPROPERTY. it worked fine on editor but kept having null as reference for the new variable but showed correct values for the old assignations.
Our team found the following error on the failing assets:
LogCook: Warning: Content is missing from cook. Source package referenced an object in target package but the target package was marked NeverCook or is not cookable for the target platform.
The BP that fails to load (child of an old BP Character) is on the same folder as the one working fine.
Have you checked if your packaging settings or a custom cook rule manager is explicitly marking the package’s CookRule as NeverCook? Some things you can try:
Right click the pawn BP > Audit Assets > see if the Cook Rule contains any value. If so, what’s the value? If there is no value, it means there is no custom cook rule that has already decided in-editor to exclude the asset, which is also good to know.
Check Project Settings > Packaging > Advanced > Directories to never cook, if that BP is in one of those directories.
If neither of those reveals something, let us know and I can pull in a team mate that can help you diagnose this further.