membership plugin doesnt work

I just bought the membership plugin through the app sumo deal - when i attempt to activate the plugin i get the following error... Please Advise.

Fatal error: Call to undefined method stdClass::set_help_sidebar() in /nfs/c04/h02/mnt/64061/domains/new.theautomoto.com/html/wp-content/plugins/membership/membershipincludes/classes/class.help.php on line 73