404 and Permalink Error

Using:
WooCommerce 2.1.12, WooCommerce Print Invoice & Delivery Notes 3.2.2

Hi guys,

plugin works fine as long as I use the standard wordpress themes. (printing works fine)
when I change to my premium theme goodnex (http://themeforest.net/item/goodnex-premium-responsive-wordpress-theme/4948491)
printing stops working and giving me an 404. Tried the tips in the FAQ but didn’t work.
developer console gives me this error:

GET http://example.com/my-account/print-order/412/ 404 (Not Found) VM1304 jquery.js?ver=1.11.0:3
(anonymous function) VM1304 jquery.js?ver=1.11.0:3
n.fn.extend.domManip VM1304 jquery.js?ver=1.11.0:3
n.fn.extend.append VM1304 jquery.js?ver=1.11.0:3
(anonymous function) jquery.print-link.js?ver=3.9.2:38
n.event.dispatch VM1304 jquery.js?ver=1.11.0:3
r.handle VM1304 jquery.js?ver=1.11.0:3

do you have any idea what the issue is here?

thx in advance

https://ww.wp.xz.cn/plugins/woocommerce-delivery-notes/