Hello! Me again. Just wanted to let you know some of the other (very few tbh!!) mods I've encountered issues with.

Maria here has a similar issue to Croatia, except even her leader name turns into the "LOC_" thing on the menu to choose your leader/civ.

Through the same elimination process I did with Croatia, I think the issue may be with Lithuania/Gediminas, as with all other mods enabled she was fine.