Quote Originally Posted by BlessIsaacola View Post
You need to install either the numinix product fields or the other mod in the admin that creates the UPC/ISBN in your product table.

In the log run the Numinix Product fields will be your best bet and the link to the mod is here: http://www.numinix.com/zen-cart-modu...product-fields

Please keep in mind that it's for 1.3.9g so you will have to compare the core files overriden to your current installation if it's newer than 1.3.9g (which should be 1.3.9h).
Thank you for the suggestion!

I see the Numinix download contains new files as well as other files that will be modified. I understand that part of it.

However, there are also separate folders with 'optional fields'? One of them is titled "upc_isbn", do I need to add those as well?

Thank you very much for your help.