Cubepoints Member Invites Plugin confliction

Hello,

I am using this plugin pro version http://wp-events-plugin.com/

When using the link below to make a booking
http://testing.youracp.org/events/level-4-diploma-credit-management-4/

The page redirects to a shopping card where the user confirms the details, how ever the booking never gets placed and the “Cart Page” states You have not booked any events yet. Your cart is empty.

I have Disabled all plugins except the events plugin and yours, i have also set it to the default WP 2011 theme, i have also contacted the WP Events plugin developer and have confirmed the p;ugin works when your plugin is disabled

Please can you advise / investigate
If you need access to my testing site them please let me know
Regards

Stuart

https://wordpress.org/plugins/cubepoints/