Unable to set up registration for membership premium

I’ve been trying to set up Membership Premium on the web site, but when I add the [subscriptionform] shortcode, the entire registration page disappears. All the text and images above the form are gone; it’s a blank page (including the header). I tried deleting the shortcode, but the page will not reappear unless I deactivate the plugin.

I tried updating the plugin to V 3.5.3.2, but was unable to make the page reappear while the plugin was activated.

Clues?

Dennis