Normally when I get that it is caused by a misstep in the activation process, my computer has unfinished installs that require a reset, or I've been doing a lot on my comp and it needs a reset to clear memory. Sometimes that's all it takes
Trainer is working solidly with the lastest patch on my end.
What I did was start the trainer start the game then while in game activate the trainer nothing seems to work. If I run the trainer then the game and activate the trainer I get an error. If I run the game then run the trainer and activate it I get an error. If I run the game then run the trainer and then activate it while running around in game I get an error. I have tried several different ways but the most viable way so I didn't get the error was run the trainer then the game and while in game running around activate it although nothing works.
Then please re-install .NET Framework 4.5, even if you have it installed. The thing is that these games are using the .NET framework and WHICH version they use depends on the system variables. Reinstalling forces the game to use that version.
If they use a different version, they have different code and the trainer fails.
well here is my situation was playing with the trainer on yesterday everything worked fine now today its having issues ive tried updating .net framework it says i already have 4.5 ive also restarted my pc, didn't work. yes im using mods but ive had them installed for the past week with no problems i think perhaps windows may have updated but i dont remember.