Hello and welcome to the community. I’m glad you’re enjoying WeMod. 
If you have the Death of the Outsider expansion, you need to use a different trainer because it is a standalone expansion. This trainer should be what you need: Dishonored: Death of the Outsider Cheats and Trainer for Steam
If you don’t have Death of the Outsider, could you ensure that your version of the game is up to date, please? There hasn’t been an update to the game since the last time this trainer was updated, so it should really be working. Verifying the files via Steam should ensure everything is up to date.
After that, try launching the game first. When on the main menu alt+tab to WeMod, press play then alt+tab back to the game.