I found a bug that occurs when a unit is moving between turns and is attacked by a monster.
When "Auto Resolve" is selected from the pre-combat screen. The scout is defeated by the more powerful monster and the scout finishes moving and dies several squares away from the sight of combat.
If the final square is one of your cities, the scout will survive with only 1 hp and will be immobilized and any attempt to go to the next turn results in the game hanging.