Tried all that and trainer still doesn't work. This is the error I'm getting in event viewer. I've added the trainer directory to the whitelist on antivirus before disabling it as well as the exclusion list.
Faulting application name: 73627-OUTRIDERS Trainer.exe, version: 126.96.36.199, time stamp: 0x5f6b3998
Faulting module name: 73627-OUTRIDERS Trainer.exe, version: 188.8.131.52, time stamp: 0x5f6b3998
Exception code: 0xc0000005
Fault offset: 0x000000000008dec3
Faulting process id: 0x722c
Faulting application start time: 0x01d72c5d1a3f298b
Faulting application path: G:\Trainers\Outriders\73627-OUTRIDERS Trainer.exe
Faulting module path: G:\Trainers\Outriders\73627-OUTRIDERS Trainer.exe
Report Id: 62118682-5d10-4332-9ba5-53128faa5e57
Faulting package full name:
Faulting package-relative application ID:
So if I understand, even with the normal anticheat and the game without any installations outside of the base game it did run? If thats the case, there may be something going on with your installation. Ive been seeing a lot of engine crashes as of yesterday, though maybe thats just on my system.
What I did was just replace the EAC and then run the game from steam, no extra arguments, nothing like that. Selected Directx 12 then activated the trainer as soon as the movie started playing (the one with the alien bird thing flying through the air).
Now with the error you are getting, I recommend completely uninstalling the game, delete its steam folder and then try installing it afterwards. (If you havent tried that yet, it may be worth a shot.) I think I understand whats going on, I just wish I had a more definitive answer to give you.
If you play the demo then you should probably use the trainer that was made for the demo.