Can't make an appointment in appointments+

I’ve installed Appointments+ on this page ( http://hiddink.nl/plan-uw-werkplaats-bezoek/ ). I’ve reinstalled the translation, but you still can’t make any appointment. This is the fact since the latest update. Before this update everything was working just fine. I’m using the following shortcodes:

[app_services]

[app_monthly_schedule … add=”1″]

[app_pagination step=”1″ month=”1″]

[app_confirmation]

What am I missing? Hope you can help..

Regards,

Martin