This error is caused by one of those reasons:
1. You have deleted the Xigncode.usa folder from the game folders.
2. Or you have purposely disabled the Xigncode windows service for hacking purposes.
3. Or that service was disabled somehow for an unknown reason.
4. Or you have purposely disabled and deleted the Xigncode windows service for hacking purposes.
Solutions:
If the cause was the first reasons, then you can find that folder online or here at this site, I've seen it somewhere.
If the cause was the second and third reasons, then you can try to restart that service manually from windows control panel->administrative tools-services.
If the cause was the fourth reasons, then you can only fix this problem by reinstalling the game.
I hope my reply would help.