Getting something very similar on 3878 (Windows Graphical, although I’m not using a texture pack currently). When moving with arrow keys or numpad the game just quickly closes with no explanation. Seems to occur more often if I’m rapidly tapping the same button, but isn’t limited to that. It keeps my save data though, strangely.
EDIT: In the last few minutes it’s started just automatically shutting down after a few turns, rendering this build unplayable.