Hello everyone and this is a fix for a common issue in WordPress 3.5.
WordPress Fix – Add Media Button Not Working
Basically you’ve just updated your install of WordPress and bang! The Add Media button doesn’t work! What to do?
Never fear, Carnfield is here – with a fix!
Basically you need to open your “wp-config.php” file in the root of your WordPress Install.
Search for this line:
require_once(ABSPATH . 'wp-settings.php');
And just before it add this code:
define('CONCATENATE_SCRIPTS', false );
Now your WordPress Install should be fixed!