You do use the trainer with the latest STEAM version of the game and run it with admin rights?
Its not the trainer, it's the game. I had the same issue of CTD and tried several fixes before I got it to the point where I could play for about an hour between crashes. Just google "Metro 2033 Redux crash" and you will see what I mean. There are a few out there that say solved or 100% fix, but they are still hit and miss unless you have the exact same as the people who say it works for them.