Error on Opening incoming friend requests

[tbworld]

Set the constant "Disable all hooks" from the config.php file. Then test using a non modified vbulletin default style. The problem should go away.

Then re-enable products one-by-one switching back and forth between your modded style and the vbulletin default style until you find the product / plugin that is giving you the trouble. Sorry there is no one-step solution. Good Luck!

The only other way is to set a backtrace from the file that gives the error.