If you are using this theme on a WordPress.com server instead of a WordPress.org self hosted installation the Redux metaboxes extension generates the wrong URLs. To fix this add the following to your child theme's functions.php file:

function ghostpool_metaboxes_css_extension_url() {
    return get_template_directory_uri() . '/lib/framework/extensions/metaboxes/extension_metaboxes.css';
}
add_filter( "redux/metaboxes/OPTION/enqueue/redux-extension-metaboxes-css", 'ghostpool_metaboxes_css_extension_url' );
function ghostpool_metaboxes_js_extension_url() {
    return get_template_directory_uri() . '/lib/framework/extensions/metaboxes/extension_metaboxes.min.js';
}
add_filter( "redux/metaboxes/OPTION/enqueue/redux-extension-metaboxes-js", 'ghostpool_metaboxes_js_extension_url' ); 

Replacing OPTION with the following depending on the theme you are using:

Socialize: "socialize"

Huber: "ghostpool_huber"

Gauge: "gp"