I have save with my world conquest with England. I have HRE vassals plus Spain, France, Aragon and lots more, since new patch changes overseas colonies to colonial countries it crashes the next day it creates colonial country for me. My thought is that my Spain vassal having too much overseas colonies creates this problem since vassals can't have vassals, right? I tried to reinstall EU4 but no luck and obviously I can't temper with ironman mode save. Hope you will find solution.