wordpress mu site install

Am trying to install the network

and I end up with not being able to log back in and I get

Warning: Cannot modify header information - headers already sent by (output started at /home/len20/public_html/lensjournal.com/wp-config.php:1) in /home/len20/public_html/lensjournal.com/wp-includes/pluggable.php on line 934

Thanks...