This machine has reached the Z8Games Accounts creation limit.

Hi everyone! I've never played Crossfire before but after a recommendation from a friend of mine I decided to give it a try. I've downloaded the game from Z8 Games webpage and tried to create an account but the message "This machine has reached the Z8Games Accounts creation limit." keeps showing up. As I said before I've never played it, or install it in any of my computers (laptop and desktop). Does any of you know how to solve this problem? Thank you