OK, so I just took the time to record yet another video showing the current trainer activating fine with the current version of game.
If you uninstall the game, make sure you manually delete all files in the Vermintide 2 folder. Run the game by itself once when reinstalled and then use trainer. Otherwise there are literally 50 other posts in this thread of things to try. Make sure you are only trying to use the trainer with bots.
[Edited by moderator Nevermore, 1/24/2021 6:05:33 PM]