Membership upgrade broke renew form

Hello

I'm using WordPress 3.8.1 and Membership 3.5.0.6. I have a subscriptions page containing the [renewform] shortcode. I'm using a custom renew form (I set it using define( 'MEMBERSHIP_RENEW_FORM'...))

When I view the page with the [renewform] shortcode I get this error
Call to undefined method Membership_Render_Page_Subscription_Renew::get_subscriptions()

Pete