Okay, first I'm sorry, because I don't have any intern text available, since the game completely crashes, including the bugtracker.
The bug only affects one save, the rest of the game seems to work fine so far. Before I saved that game the last time, it already was bugged; it started when I loaded it the last time, when the whole earth turned green. The first mission I played on that green earth didn't display any graphics but my troop transporter, the enemy spaceship, my soldiers and visible aliens. So after winning that mission wich went just fine with alot reaction fire I decided to save and play another time, but now it won't even load. When I load the game, everything crashes, and windows says: UFO:AI stopped working.