Brief We have updated the 'admin_product.php' file for version 3.6. Description. A few options were not copied when duplicating a product, namely: Quantity Prices Downloadable Files Serial Numbers Solution. We would recommend you to download an updated version of the file from the link below. Further, extract the above mentioned file into the 'admin' folder of your shop replacing an existing one. Don't forget to make a backup copy of the current file in case something goes wrong.