As I wrote, once I had sucessfully finished my CK-game in AGCEEP, so I think there should not be a problem with convertion...
While playing it there were some events which should not be existing- eg. my Castile received event about Bohemian troops, Shiites uprising in Timirud Empire and so on... But in this game they disappeared

I'll try to localise as many "bad" events as I can, if I could only play...
Third Angel- AGCEEP is the best mod and I don't see any sense playing in vanilla any more... No events, stupid structures, no options...

But in vanilla game does not crash, but I didn't try to save it...
Ok, I'll try with dots as I can't see anything else which I can easily fix
EDIT: Oh, maybe this will help: I played this exported game in vanilla, saved and moved save to AGCEEP. Countries changed but there is no AGCEEP events or options... Game does not crash and it saves.