I've found it. My domain is set to https. So one needs to alter the following file:
administrator/components/com_jem/vieuws/venue/view.html.php
Line 59 reads:
Code:
$document->addScript('http://maps.googleapis.com/maps/api/js?'.(!empty($key) ? 'key='.$key.'&' : '').'sensor=false&libraries=places&language='.$language);
This should be changed to
https
Code:
$document->addScript('https://maps.googleapis.com/maps/api/js?'.(!empty($key) ? 'key='.$key.'&' : '').'sensor=false&libraries=places&language='.$language);
I think this should be done by default, since the https doesn't affect http sites.
