Quote Originally Posted by Asai Nagamasa View Post
I'm afraid there's no way out of it.
Uh, yes, there is a way out of it.

Look at the screenshots I posted. The king was "destined" to die once I hit End Year in the savegame. I fiddled around until he didn't. He now lives, and unless he dies "again" (in which case I'll reload and undo it) the heir should be along in a few years.