If you’re into Arma 3, you might have come across the message, “Files are not signed by a key accepted by this server.”
This error usually occurs when you’re getting the latest version, putting it on your Arma 3 folder, and enabling the extension within the game. But luckily, we’ve got fixes for you! Our tech team details this brief guide to resolving this error.
Fix #1: Check the Mods Needed and Compatibility
First of all, you’ll need to check the mods you’ll need for Arma 3, and if that’s compatible with the game server, you’re on.
If you don’t have any mods yet, we suggest the following mods:

- Enhanced Movement
- Unsung
- Kunduz, Afghanistan
- Operation: Trebuchet
- Cup
Fix #2: Redownload mods
Check for the “.bikey” files within your keys folder. If you can’t find any, you don’t properly sign the mod, so it won’t work. To fix this, try to redownload the mod [1].
Fix #3: Delete the Keys Folder
This time, you can try to delete the keys folder. There may be rogue files saved somewhere, which causes the error. So, we suggest deleting the folder.

Fix #4: Verify the Integrity of Files
To resolve your concern, try verifying the integrity of the game files. Here’s how:
- In your Steam library, click “Arma 3.”
- Click on “Properties.”
- Go to the “Local Files Tab.” Select “Verify Integrity of Game Files.”
- Just wait for the process and return to the game.
Fix #5: Reinstall Arma 3
Your last resort is to reinstall Arma 3 on your device. Do a clean uninstall of the game, then download and install it again, just like you usually do on other games.
Reinstallation may refresh the game – getting rid of the errors you’ve encountered.
