Reply Problem after upgrade

[Battle_Ring]

I get this every time i reply

Unable to add cookies, header already sent.
File: /home/wholesal/public_html/biggestloserfans.com/includes/class_core.php
Line: 4501

All plugins have been disabled

[Lynne]

And what is on line 4501 of your class_core.php file?

Try disabling your modifications/plugins and see if you still have this problem.
Note: To temporarily disable the plugin system, edit config.php and add this line right under <?php

define('DISABLE_HOOKS', true);