I have more info on this problem.
I’m using WordPress 4.0 with “Use Google Libraries” 1.6.2 and the Add Media button does nothing when I click it.
I’m using Chrome 38.0.2125.111 but the same problem happens in IE 11.
As a test, I disabled all plugins except “Use Google Libraries”, and changed the theme to Twenty Fourteen.
When I edit a page in the admin area of my blog, I get the following error in the Chrome JavaScript console as the page first loads:
Uncaught TypeError: undefined is not a function postbox.min.js?ver=4.0:1
I swapped the contents of wp-admin/js/postbox.min.js with the contents of the non-minified version of the script (postbox.js), and then I get a better error message, which points to line 78:
Uncaught TypeError: undefined is not a function postbox.min.js?ver=4.0:78
Line 78 is the following line in postbox.js in the “init” function:
$('.meta-box-sortables').sortable({
When I search for “meta-box-sortables” in the source of the admin page, I find the following three references:
<div id="side-sortables" class="meta-box-sortables">
<div id="normal-sortables" class="meta-box-sortables">
<div id="advanced-sortables" class="meta-box-sortables">
As TomCobbley said, WP_DEBUG doesn’t output anything related to your plugin.
When I disable “Use Google Libraries”, the JavaScript console error goes away, the Add Media button works again, the three div’s are still there, and I see in the source of the admin page that “postbox.min.js” is no longer being loaded.
I’m a web developer myself — let me know if you’d like me to try something.
Thanks,
Russell