I just had the same thing happen again. I had (luckily) saved my game prior to my previous crash, so I loaded from there and went into another ground battle and once I landed I saved from there, then the ground assault went all the way to the end. Each time I'm only finding one alien on each ground attack (and they're always in the same location of the map?) so I went to where I knew it would be and once he was dead, then on the next "Hidden Movement" the game locked up and never recovered.
I'll try a few more times from the last save I made (from where I landed) and hopefully I can get my next save to happen once I'm back to base.
** Update: I did try a few more times and the only way I can proceed in the game is to save often, but the over all game has now locked up several times and always during "Hidden Movement" and its making it very frustrating. If there's any suggestions anyone can offer then I'm cool with trying anything.
Also, on a whole other topic but why do nearly all the smaller UFOs I destroy no matter where I shoot them down it says they all crash into the sea? Even if I'm clearly over what should be land they still fall into the sea.. sucks cause I wanna go investigate those guys. I'll look for another thread to post this on but it was fresh on my mind.
I'll stop posting comments on this problem for now. With as many other people posting then I'm sure the devs are aware there's a significant problem.