Need to know did you do anything special? Because when I load the game, Norse scandinavia seem to be Shia, Catholic and Orthodox has swapped places. And the cultures in the world is totally messed up. Basically the entire save is broken. Have you tried to edit the save(just opening up the file could be enough)? Be honest 
Anyway if it is not that then did some kind of major thing happened? Anything you can think off might help.
Anyway if it is not that then did some kind of major thing happened? Anything you can think off might help.