Microsoft and Epic Games implemented severe automated anti-cheat tracking for Gears of War 3 . Impossible progression spikes (e.g., getting all Onyx medals in one second) will trigger an automatic, permanent account ban from the game's servers.
If you want to move forward with setting up your files, tell me you are playing on (Xbox 360, Xbox One, or Xbox Series X/S) and what specific items you want to unlock (skins, campaign progress, or medals) so I can guide you on the exact tools required. Share public link gears of war 3 save editor link