Left the game running overnight, now it lags and lags and finally crashes

I played for about two hours last night. I exited my game (to title) and went to bed. 8 hours later when I went back in, this game got slower and slower and began saying the clock was behind 4 seconds, etc.  I have shutdown and rebooted but get the same reaction from this game.

Games running on 12.2 don't have this problem.