I am using 1.47 version of the trainer so I don't know if this issue is updated or not. I just started the game and got to level 8. I then increased my level to 15 (using NumPad9) and I noticed that in the game I stopped leveling up. Is there a way to decrease my level back to my original level so that I can start leveling again?
I don't the game installed anymore so I can't confirm it but your issue is probably that you don't have the experience required to level.
You increased your levels but not your experience so until you've earned all the experience from 8 to 15 you won't get 16.
No dose not work, other trainers work perfectly, just this one dose not launch.
Launches fine here Link
Delete the trainer, get ccleaner and run both the cleaning tool and the registry cleaning tool, get a new trainer, exclude it from scans Link and run it as ADMIN.