Just throwing this out there. I've seen some of us are in the same boat with the issue of the trainer not finding the game then closing. I bought the game on Uplay (only one in world it seems). Everything is closed, exited, ended, etc. Open the trainer, find the game directory with F2, do all the crazy steps some people say might work, press F1 and uplay starts to open the game. after like 5-10 seconds, the trainer says "TRAINER CANNOT FIND GAME" then it closes and leaves me on the far cry 5 game screen in my uplay launcher. Tried the "FAQ" it didnt work or address the problem I any a few others have. I'm cool with playing without a trainer but I dont want this problem blown off as "they're just not doing it right". I'm not sure what the issue is but i've tried plenty of times to get it to run so i'm going to stop trying and wait for the trainer updates. maybe some day i'll be able to use it.
Nowhere in the trainer instructions does it tell you to use F2 as the very first thing to do. Please try again.