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 "" from accessing a frame with origin "". 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

Kind regards

Kenny Van de Velde