I get this errors:
Uncaught TypeError: Cannot read property ‘mozilla’ of undefined at jquery.tools.min.js?ver=5.3.2:242
Uncaught TypeError: jQuery(…).tooltip is not a function at (index):364
(<– where the toolptip is)

WP version: 5.3.2
php version: 7.2.1
jquery version 3.4.1

I think it has to do with the version of jquery.
I found a workaround. Put this in your functions.php file of your theme:






function my_theme_enqueues(){



        wp_dequeue_script( 'mci-footnotes-js-jquery-tools' );



        wp_register_script('jquery-ui', 'https://code.jquery.com/ui/1.12.1/jquery-ui.js', array('jquery'), null, false);

wp_enqueue_script('jquery-ui');
}



add_action('wp_enqueue_scripts', 'my_theme_enqueues', 100);