Disable plugins via config if this fixes the problem
To temporarily disable the plugin system, edit includes/config.php and add this line right under <?php
PHP Code:
define('DISABLE_HOOKS', true);
To enable plugins again just comment out the line
PHP Code:
//define('DISABLE_HOOKS', true);
if not leave plugins disable and upload the tools.php you will find this file in the do not upload folder of the vbulletin pack that you get from the members area