Users Report Frequent Header Errors

[King Justice]

Hi.

A lot of my users frequently report having this error:

Unable to add cookies, header already sent.
File: /usr/local/psa/home/vhosts/egamingsupply.com/httpdocs/forum/includes/class_core.php
Line: 3036

Some of them always get this and cannot post or create new threads.
How can I fix? Not everyone gets this error...I'm an admin and never got the error myself.

A lot of my users do though. :(
Please assist.

[da420]

Start off by disabling hooks to determine if it's one of the plug ins that is causing this.

http://www.vbulletin.com/docs/html/main/disable_plugins

[dmperry24]

It's the unregistered users or those that aren't logged in that get the error message. I don't know what to do to cure the problem though.:o