READ TRAINER NOTES. I will ignore any comments that ignore trainer notes.
ACTIVATE CHEATS BEFORE A MISSION LOADS OTHERWISE GAME WILL CRASH!! During the main menu or loading screen but before mission loads.
The recent update to game changed a lot of stuff in the game that made the trainer NOT work as it should when the mission loads. This explains the crashing issues you were experiencing.
I also don’t know if this has something to do with WeMod v6 update and the denuvo protection that’s itself included in the game conflicting.
You can use trainer fine if you enable the cheats before a mission is loaded.
The issue with XP/Skills were all a result of this.