Free Gateway Button Not Appearing (Error in Thread)

Hi,

I'm having an issue where the Fre Payment Gateway button is not appearing on the registration form.

I turned on WP_DEBUG and received this error:
Notice: Undefined index: formtype in /home/healthyw/public_html/wp-content/plugins/membership/membershipincludes/classes/membershippublic.php on line 2097

This definitely seems to be related. The cell for the button is just straight up not appearing.

Any help would be much appreciated