So the game used to work OK for you, and now does not, is that right? Did it break after a patch, or installing a mod, or what?
Try deleting or renaming the Documents CK2 folder (obviously move any valued save games elsewhere first, and let the game recreate it with default settings.
If that doesn't help Try a full clean reinstall:
If this is Steam: move any valued save games elsewhere and uninstall the game from within Steam. Then manually delete ALL the CK2 directories from under BOTH the Steam and MyDocuments folders. Now reinstall the game from Steam, and run the Verify just to make sure it all came down properly.
If this is GamersGate: Move valued save games elsewhere, and uninstall the game. Manually delete the CK2 directories from where GG put them and from MyDocuments. Reinstall the game (this time pick somewhere NOT under the system path c:\program files\ ), download 1.111 patch again and apply it.