Kits reverting to generic in cup competitions

Has anyone had trouble with kits reverting to generic in cup competitions? The kits are normal in league play, but they change in game when in all cups. The opponents kit on the screen doesn't change though. Is it a bug or a problem with a certain config file?

It's not a bug, it most likely licencing issue. Almost all big teams who qualified for EU competitions are affected. If you go to the editor and check colours and kit section of affected clubs, you'll see that they have multiple shirts (and other kit items) assigned. So, for example, one shirt will be assigned to cup, other to championship league and so on. You have to remove all items that are assigned to a competition, and leave only items that have no competition at all assigned to them. For careers in progress you can use in-game editor for that.
Here's more detailed instruction:
https://sortitoutsi.net/forums/topic/39065/how-to-get-your-3d-kits-to-work-in-champions-league-etc?page=1#comment_414627

I see. Thanks for clearing it up, man!