For the record. My mission crashed too, they just wouldn’t follow me. I managed to get through it second time though (Treyhearn died a number of times too, my bad). The key I think is to make sure you do things in the right order. I didn’t get into a fight outside the cave entrance you blow open and as you go into the cave for the 2nd team, stick to the right hand side and don’t get carried away spamming your long distance shots accidently pulling baddies from round the corner before you free the 2nd team. That’s really the only thing I did differently. Good luck. It is a long mission to keep playing, my sympathies to anyone who had to do it more than twice, ha ha.