If you are running a different patch (like 1.03 or the Gentool mod), the trainer will likely crash or fail to activate.
Unlocks all 5-star General abilities (like the Fuel Air Bomb or Carpet Bomb) at the very start of the match. command and conquer generals zero hour trainer 104
If you use "Instant Build," sometimes the AI also gets the benefit. This can cause the AI to flood you instantly. Look for a trainer that specifies "Player Only" for instant build features. If you are running a different patch (like 1