Hey,
I am using easyReservations 3.2.4 on WordPress 3.5.2 – so, both should be recent.
When opening the easyReservations dashboard, the calendar does not show up.
Checking the Java Console on Chrome, it says this:
XMLHttpRequest cannot load http://domain.de/wp-content/plugins/easyreservations/overview.php.
Origin https://domain.de is not allowed by Access-Control-Allow-Origin.
So it seems, the http:// is hardcoded, and it doesn’t care if you use https or http.
While using http, the error doesn’t happen.
Would be happy to get a fix from you 😉