Sniper Elite 3 trainer refusing to activate f2 hotkey

yes I know this game is old and I do run the game on a previous version (v1.06 so the trainer is of course v1.06) and I can't activate the trainer which is the f2 key. if you can tell me on how to try to fix this I will attempt to do that (I opened the trainer multiple times and redownloaded it a couple of times).

ps: it was working the night before with the f2 key, I did test the keys with them working and I'm on a retail version.