Aliens vs. Predator (2010)
I think the issues seems to be on entering the monorail station and Tequila mentions the Alien below (feeding on a corpse) killing it from above breaks the level scripts.
If you ignore it and allow it to attack the synthetics across the tracks everything seems to run smoothly afterwards. I've only tried without the trainer running but I'm about to run through it again....
Play from the levels beginning without the trainer (I restarted the game and left the trainer alone (not running) to make sure) and don't shoot the Alien on the platform until it's attacked the first set of Synthetics. This seems to have worked every time, good luck