A few more things to try:
1) Try cancelling all auto moves, saving and restarting game.
2) Go on an attacking spree, kill every monster/enemy you reasonably can, then save reload game.
3) Try cancelling all city construction/unit projects save and restart game.
4) Try deleting all the units you don't need, saving and restarting game.
It is highly likely one or any combination of the above is going to work.