You are using " wkzero_ship " named shipment plugin. this plugin causes the error. if we disable this shipment method everything works fine. please attach that shipment plugin. so we can make our plugin work that shipment too.
Thanks for your answer. I attached the plug-in wkzero_ship.
Your help is also required for Onepage checkout (offcanvas) configuration. Even when the plugin Wkzero_ship is disable, we are unable to make the Onepage checkout work with our yoo_avanti template. If you can have a look ?
Thanks by advance