To reproduce this crash, use this save game, then go to the military screen. Attempt to go down two squads. Reproduces in 31.03.

Occurs during a siege. No clue why it happens, but I made it happen twice on 31.02 and once on 31.03, the exact same way. The game just shuts down. When it was 31.02, it told me that DF had stopped working; now it just locks up and poofs.