If you run into issues, try running the trainer after the game reaches the main menu, and make sure no overlays (Discord, EA overlay) are interfering.
Here’s a helpful write-up on the Crysis 3 Digital Deluxe Edition trainer, covering what it is, what it typically includes, compatibility notes, and responsible usage tips. A trainer for Crysis 3 Digital Deluxe Edition is a small third-party software utility that modifies the game’s memory in real time. It allows players to activate “cheats” or gameplay adjustments that aren’t normally available, such as infinite health, unlimited energy for the Nanosuit, or infinite ammunition. crysis 3 digital deluxe edition trainer