generated 500 internal server errors

[Sat Jun 15 18:09:35 2013] [warn] [client 66.249.73.83] mod_fcgid: stderr: PHP Fatal error: Call to a member function find() on a non-object in /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/follow-nofollow-control/nofollow-control.php on line 124

Webpages with nofollow generated a 500 response rather than a 200