Error Popup Pro not visible

Hey Support,

I've just created an account at this website, and tried to install the popup Pro.
But when i activate the popup he is not visible.
I don't know what the problem is,
i get this error message in the javascript console
Uncaught SecurityError: Blocked a frame with origin "https://www.google.be" from accessing a frame with origin "http://www.group-f.be". The frame requesting access has a protocol of "https", the frame being accessed has a protocol of "http". Protocols must match.
this is the page where the popup should be visible
http://www.group-f.be/hoogwerkers/

Kind regards

Kenny Van de Velde