Welcome to the community @toni000. 
This usually means one of two things:
-
There are specific instructions that you need to follow to get the trainer to work correctly. These instructions are included in the trainer itself.
-
You need to change the order that you launch things. See here for more information: 32 bit and 64 bit.
If you’re still struggling:
- What game are you playing?
- Which store did you get it from or is it cracked?