Can't log into vbulletin admin, get error!
 

I get this error whenever I try to access vbulletin admin panel, how can I fix this?

Warning: require_once([path]//includes/defines.php) [function.require-once]: failed to open stream: No such file or directory in /home/content/d/e/r/***/html/administrator/components/com_jfusion/plugins/vbulletin/hooks.php on line 454

Fatal error: require_once() [function.require]: Failed opening required '/home/content/d/e/r/***//html/discussions//includes/defines.php' (include_path='.:/usr/local/php5/lib/php') in /home/content/d/e/r/***//html/administrator/components/com_jfusion/plugins/vbulletin/hooks.php on line 454