I installed a modification for my vbulletin suite and got this error

"Fatal error: Using $this when not in object context in /var/www/forum/includes/class_hook.php on line 57"

Apparently some users have this error when using the mod with vbadvanced, but theres no support given.

Maybe someone can figure it out. I don't have any php-knowledge, so i appologize in advance

This is line 53 - 58

53 * Sets the plugin list array
54 */
55 function set_pluginlist(&$pluginlist)
56 {
57 $this->pluginlist =& $pluginlist;
58 }

I hope someone can help me, also it's not very much information :/