I modified includes/languages/english/classic/header.php with a simple text change, but after saving the change and loading the page, I get this error:


Warning: Cannot modify header information - headers already sent by (output started at /home/mykids/public_html/store/includes/languages/english/classic/header.php:1) in /home/mykids/public_html/store/includes/init_includes/init_templates.php on line 78

For the life of me, I cannot figure out what that means, or what to do about it.

Any help is much appreciated.