Apparently I've found this bugs:
#1: If you try to load a previous game it glitches to the main menu
#2: If you load it again, it will be successful but the issue is that the game will be so glitched that it will be unplayable because you can't change turns, open diplomacy menu (actually any menu really).
#3: Before I found those bugs I found another one which basically means I had to get out and reload the save file when I traded territories, annexed territories in peace treaties etc. This happened to the AI also.