I also had the same problem... after some digging, it looks like the problem is in /wp-content/themes/enfold/config-templatebuilder/avia-template-builder/assets/js/avia-media.js, line 26:
$.AviaElementBehavior.wp_media = $.AviaElementBehavior.wp_media || ;
$.AviaElementBehavior.wp_media_advanced = function()
var $body = $("body"), file_frame = , media = wp.media,
The problem is that 'wp' is not defined in
media = wp.media.
I changed the last line as follows:
var $body = $("body"), file_frame = , media = $.AviaElementBehavior.wp_media, // wp.media,
Now everything works fine... I did not contact the Enfold team yet on the issue.
Hope that helps,