This error message (InnerMessage:Hard128048Invalid commodity code for product number 8. Valid length is 6 to 15 alphanumeric) from UPS occurs when an item in your order is missing a commodity code or has a code that is fewer than six alphanumeric characters long. To resolve this:
Click Orders then Overview, search for the affected order.
Click Actions then Details.
Navigate to the Items tab.
Click View Product for each item in the order to identify the one missing a commodity code.
Add the correct commodity code and try creating the shipment again.