I went to play this game (STEAM version) for the first time in years. I am unable to run the trainer as it says "Trainer cannot find game". I've verified that the game is up to date through Steam and came back okay. I've tried checking and unchecking the D3D12 option, as well as running the DX11 and DX12 versions of the game. Made sure AV is off, and in case, allowed the trainer. I've also tried running DX11 and DX12 versions of the game directly, bypassing Steam with no change.
I was able to resolve this issue based on a previous post I read about Nvidia Experience and reverting the changes. I ignored that previously as I hadn't opened Nvidia Experience or even signed into it, so it shouldn't be optimizing games as you usually need to run a game at least once for it to work usually.
Anyway, here's the steps I took to resolve it:
1. Open the trainer.
2. I had opened Nvidia Experience, remembering my credentials and sign in.
3. Run the game and verify the D3D12 option is unchecked.
4. Allow NE to detect the game and figure out the optimized settings. You can tell that NE is optimizing as it takes a very long time for the game to load.
5. I then went back into NE confirmed the changes were made, pressed the revert button and the game instantly loaded.
6. With the game at the main menu (after the configuration menu), activate trainer.