Persistent crash on specific date.

Ironman, Dornish lord of Red Dunes. The save game loads normally but after three or four months, more or less 23 March, the game crashes. I can't think of any reason why. I can't upload the file here, but on the Paradox forums I did.

forum.paradoxplaza.com/forum/index.php?threads/game-hangs-and-crashes-on-a-specific-date.1064551/