Scenario:
FancyBox is enabled for ‘Images & Inline content’ at Settings -> Media.
A Page or a Post shows WordPress gallery using this sample shortcode:
[gallery ids="729,728,727,676" link="file"]
WP Supersized is active.
As long as Supersized is not used on this above Page/Post having the gallery of linked thumbnails, clicking on any thumb will bring up the bigger image in FancyBox just fine.
But if Supersized is used on the galleried Page/Post, the following problem comes up:

RavanH, author of Easy FancyBox wrote:
the conflict seems related to the jquery.animate-enhanced from wp supersized and the jquery.easing used in my plugin.
Searching for jquery.animate-enhanced in wp-content/plugins/wp-supersized/includes/WPSupersized.php shows:
wp_register_script('jquery_animate_enhanced', content_url().'/plugins/wp-supersized/js/jquery.animate-enhanced.min.js',array('jquery'),self::supersized_jquery_animate_enhanced_version);
In order to disable jquery.animate-enhanced, we can use wp_deregister_script() like so:
Add the following at the end of child theme’s functions.php (before closing PHP tag, ?> if any):
add_action('wp_enqueue_scripts', 'add_my_code');
function add_my_code() {
wp_deregister_script('jquery_animate_enhanced');
}
Now clicking on linked thumbs will work fine as expected.



