Featured Image Slider Disappeared

Hey dusty909!

Please add the below code in functions.php

function modify_jquery() {
if (!is_admin()) {
	wp_deregister_script('jquery');
	wp_register_script('jquery', 'https://code.jquery.com/jquery-1.11.3.min.js');
	wp_enqueue_script('jquery');
}
}
add_action('init', 'modify_jquery');

You are probably using an old version of the theme. We have released an enfold update to match the changes made in the latest version of wordpress 4.5
If you are not using a child theme please backup any custom changes you may have added to the theme and update enfold to latest version 3.5.2 make sure you have the correct API key from themeforest.
If you are not able to view the update option in wordpress dashboard. Please update the theme manually via FTP following the steps provided here http://kriesi.at/documentation/enfold/portfolio-item/update-theme-files-with-ftp/
Once you have updated to the latest version you can remove the above code from functions.php

Regards,
Vinay