I did a bit more analysis on the problem: It is concerned to unit movement. As soon as a unit is moving (independend of own or foreign) The game hang when destination position is reached. If the computer starts with a move it will immediatly hang after this move. In this case restart will not help as the battle starts from scratch.
In case you will start you can fight as long as you do not need to move a unit. If the computer moves it will hang again but often the fight is able to continue on continue after restart.
With this it shoudl be possible to identify the problem hupfully it gets fixed soon.