Some time ago Google started requiring API key for maps in order to display the map. This works fine on some sites without the key (as in our demo for example) but on some sites you must use API key from the start.
You can enter your maps API key in your Real Estate Script Control Panel > Settings / Visual.
Follow this link to learn how to obtain the Google Maps API key:
* Sometimes in order for the settings to appear you have to first add at least one location.