So I'm playing Korea, and I seem to be stuck at war with the Mongol Khanate. The only problem is that they don't exist anymore. They were eaten by the Oirats. If I try to sue for peace, it just takes me to the Oirat province where the Mongols used to be. This wouldn't be a problem normally, but I can't annex any of my vassals because they are apparently also counted as being at war with them, even though the information about them lists no such war. Is there any way to get rid of this war?