Solutions to Common Problems
When viewing my board, I get an error that says "Cannot add cookie information, headers already sent"
The most common reason for this is a blank or exta line in your config.php. You are not allowed to have anything outside the <?php and ?> delimiters. Not even a space. It is recommended to eliminate all extra lines and spaces before or after these delimiters.
I installed a new plugin and now my forum doesn't work. I can't login into the Admin Control Panel to fix this.
To temporarily disable the plugin system, edit config.php and add this line right under <?php
define('DISABLE_HOOKS', true);
I have several domains pointed to my forums. However when users login via one domain, they get an error that says "In order to accept POST request originating from this domain, the admin must add this domain to the whitelist".
That error can happen when you post to a vBulletin form from an external referrer that isn't on the white list:
Admin CP -> vBulletin Options -> General Settings -> Post Referrer Whitelist
Edit this list to include all referrers that you use.
I have tried the above but cannot log into my Admin Control Panel to make the changes.
You can temporarily disable the Whitelist by editing your config.php file. Open this file in wordpad and in a line above the ?> add the following code:
define('SKIP_REFERRER_CHECK',true);
Please view the source of the page and compare the error to those listed in the section on troubleshooting MySQL. If the error isn't listed there, please open a support ticket at https://www.vbulletin.com/go/techsupport/