As far as your problem goes, is this in a save that no mods have ever been used with?
If so
Please do a full **clean** re-install:
- move any valued save games elsewhere
- "uninstall" in Steam-CK2
- manually delete both the Steam/SteamApps/common/CK2 AND Documents/Paradox/CK2 folders
- re-install game in Steam, run a Steam Verify when done.
- add ck2game.exe to the exceptions list/whitelist of your antivirus app
In particular make sure there are no files or folders left under either the Steam CK2 or Documents CK2 locations, before installing again.
Then start the game with no mods active and test with a new campaign.
Good luck!