I installed improved whos on line and got some error messages so i uninstalled
but i still get the following error and it shows up on my live home page to

Warning: Cannot modify header information - headers already sent by (output started at /home/sites/odinsminiatures.com/public_html/odinsshop/admin/includes/languages/english/whos_online.php:64) in /home/sites/odinsminiatures.com/public_html/odinsshop/admin/includes/init_includes/init_templates.php on line 36

can someone tell me what this means and how to correct it please, have tried everything i can think of, doubled checked i had removed all added code but nothing works.

Thanks
Michelle