what should i do to fix that error !

This should most likely work,


- Uninstall the game completely
- Disable your antivirus' realtime protection
- Redownload the game
- Install the game
- Add the entire crossfire folder to your antivirus exceptions
- Re-enable realtime protection

If you downloaded the game with your antivirus active, it may be 'cleaning' the rez file upon download.