FYI - tried to add my email on your site and received error Warning: Cannot modify header information - headers already sent by (output started at /home/bicyclc

FYI - tried to add my email on your site and received error Warning: Cannot modify header information - headers already sent by (output started at /home/bicyclco/public_html/download.php:4) in /home/bicyclco/public_html/download.php on line 48