Membership signup pop-up not working

Hello,

i've installed Membership plugin, defined level and subscription plan called "Good morning".

I am protecting only part of the content and this works great, you can see it here:
http://www.remotefitnessclub.com/temp/programs/good-morning/

Above the protected content i tried to add subscribe button for this subscription plan using the shortcode from your manual.

The button is there, but for some reason pop-up is not working properly. Instead of pop-up new page is loaded.

Can you help me with this?

Thanks,

Veljko