You could try deleting all of the files in the '
..\Divine Divinity\Run\Dynamic' folder, and then check the save again.
This folder is used as a cache for the game. Files are created / copied there from the save game folder when you load, and written / copied from that folder when you save a game. The files will be re-created as required the next time you start Divinity. If there was a corrupt file in that folder, deleting the files should fix the problem.
If you reload the save before entering the castle, you can just do Janus' quests to see if the cutscene will hang again, or not. You can get back into the castle afterwards to loot.
Check your PM (click '
My Home' in the top menu bar, then 'Received Private Messages').