If your custom piece doesn't appear, ensure it is at the bottom of your applied mods list in the Manager; the lower a mod is, the higher its priority in the game.
Point the manager to your FIFA.exe file in your installation directory. 🚀 Managing Your Mods fifa mod manager 1.1.0
Key difference: FIFA Mod Manager 1.1.0 is lighter but lacks modern encryption bypasses. If your custom piece doesn't appear, ensure it