I am sure there is something related to right clicks memory. I have already experienced this in one of my maps (The Empire) where after a few months the game could not display anymore hints on right click. Now I get a message "Out of memory" after a while. I will post here the screen, when I save it. With the new combats mechanics, there are some 25-30 right clicks /battle and multiplied by 400 battles, it just exploded the game memory.

Quiting the game and restarting solves the problem.