I have not been able to play the game for few months

Every time I load the save game the game starts loading the situation and then boots me to desktop.
If I start a new game, the tutorial part goes well all the way to the end, but when going out for the "1st real patrol" the game loads and then boots me to desktop ?!?
No crack, No mods and Game updated.
So the game has been in my hard drive since I bought it, but haven't been able to play it for months. I have been waiting for Ubisoft to update the game, but seems that is not going to happen
Is this DRM issue? or is there someother known reason for this?
Appreciate the answer, if some fellow player knows the reason