The game was updated

This is quite rare, but occasionally, a game will be updated from 32-bit to 64-bit. If this happens, a new trainer will need to be created. If you are sure this is the case, please let us know by posting in the trainer's discussion.

The game has a launcher of different bitness

Some games have a launcher that does not match the game's bitness. There is no easy way to know if this is the case, but you should go ahead and let the game finish launching, then alt-tab and click play again. If the error still occurs, this is not the issue.

The game has anti-tamper software

You might receive this error if the game has anti-mod and WeMod cannot inject. Please check the trainer info for special launch instructions.

None of these solved my issue

Please post on our community forums if the issue persists and none of the above applies.