
Originally Posted by
mc12345678
If you truly copied all of the files of your store from includes/modules/pages/checkout_shipping to includes/modules/pages/checkout_one, then that would be a source of the problem.
The only software from the checkout_shipping directory above needed to support this plugin is that added to that directory to support this plugin. So namely first the javascript file and then possibly some of the code that is inside the header_php.php file, but not that entire file.
I've been working on a slight rewrite to pull code out of that file and make a few other improvements.