I use the Steam 1.5.0. version just about every other day, run As Admin, and it works fine here. Just tried it again, too.
Just turning off your AV often isn't enough. They usually still have a component running in the background like Real Time Scanning which can cause what's happening to you.
[Edited by Jaks, 10/11/2019 10:35:36 AM]
There should be a Debug folder in the Cheathappens folder in your User directory unless the UPlay PLUS version is different. Usually here:
C:\Users\Your Name\Cheathappens\Debug\Assassin's Creed Odyssey.debug
The Debug file can be opened in Notepad. I'm not positive but there might not be any data since you reported it shuts down prior to activation but you might as well check.
Btw, which Anti-Virus product do you use? Also, what's the name of your game's Exe file? The fact that other trainers have worked doesn't help explain why this one is closing. It just means that other trainers have worked up until this one.
[Edited by Jaks, 10/12/2019 3:34:44 PM]
Steam & UPlay version or UPlay Plus?
Do you use the Stealth option? If you do, try what the Readme suggests.
Toggle the arrow option off and toggle off the Stealth option and see if that helps. Make sure you have at least some of all of them, too.
Mine is to the point that the arrows now won't decrease no matter which way I have it set.