Troubles with server

i'm in need of some help with my server there is a problem logging in this error comes up if you could help me that would be great thanks.

http://i52.tinypic.com/10zxyip.jpg

check your clients ip add, if you had not set them,
use Hex editor. open the fiesta.exe, search for error door then find the #'s below it like xxx.xxx.xxx.xxx then change it to your server's ip which is found on the config.