Mine is 4.19.2 - might be the issue, I guess I shall try updating. In the meantime I did find the problematic asset, my main model - renamed it at the beginning, showed no signs of problems but I guess it was allergic to that after all. Now it’s fixed.
Moved the assets in small groups to a new project and checked packaging for the error - and when the model was copied over: boom. Easy - just timeconsuming as hell.
