JS error in ticket edit page

Hi, with 6.0.13 version we are receiving a JS error in the browser console:

Uncaught TypeError: $.magnificPopup.instance is null
    <anonymous> https://www.site.com/wp-content/plugins/awesome-support/assets/admin/js/admin-popup.js?ver=6.0.13:42
    jQuery 2
        e
        t
admin-popup.js:42:17

Can you please assist?

Regards,
Roberto