It is generally recommended to start Far Cry 5 and reach the main menu before hitting the "Activate" button on your trainer.

Disclaimer: This post is for educational and informational purposes. Modifying game files violates Ubisoft’s ToS. Use at your own risk and never in online modes.

If you attempt to use a v1.09 trainer on v1011, your game will likely freeze when you press NUMPAD 1 for infinite health.

Remember that your Gold Edition includes all DLCs, which the trainer should also support for the single-player portions.