Forum Error - Cannot modify header information
 

Cannot modify header information - headers already sent by (output started at /home/combatar/public_html/vBulletin/includes/config.php:1) in /home/combatar/public_html/vBulletin/install/authenticate.php on line 55

I get this error after i put my customer number. Anyone can help me? Thanks and sorry if i post in the wrong forum.