Having a Mare !!!! I cant run a Default Membership Plan

Hi all, I am running ARMember Pro in my new clients site and the Membership if Free. When the User Registers I am trying to make it so the new user is given the Free Membership by Default – I have tried ‘[arm_form id=”101″ assign_default_plan=”1″ logged_in_message=”You are already logged in.”]’ but nothing, appart from on the ‘General Settings’ / ‘Page Setup’ where it shows the Registration page it has now come up with – ‘Shortcode of Registration Form not found on selected page. Please add shortcode on that page Or please select appropriate page.’ ??????? All in Alll this is getting so, trouble being at the moment being the site is only ‘Local’ at the moment, I have a meeting with said client this coming Saturday the big ‘Show’ so to speak so please any suggestions would be spot on !!!!!!