I'd love to see trainers for the GoG versions of games, but they seem to focus on Steam exclusively.
Some of the trainers work with the GoG versions regardless, but it's hit or miss.
The trainer for this game doesn't work with the GoG version unfortunately.
Please verify if the versions of the game and our trainer still match (current is v1.0.13832).
Also, please make sure to have scan exclusions created in your security software for teh trainer exe file and the Work folder. This Work folder is located here -> C:\Users\YourWindowsUserName\Cheathappens\
Clear the Windows Temp folder, reboot your PC and launch the trainer with admin rights, then the game and activate pressing F1 in the game's main menu.