One thing for sure... the trainer will SURELY & ABSOLUTELY DOESN'T WORK IN MP & ONLINE since change only be recorded in your game not in others so its won't work !
1. Check your game version
2. Check game forum
3. Btw if u using a cracked no cd game then u can kiss bye bye to your trainer since the cracked version had modified the original .exe while the trainer will try to look for the original .exe