Work with Purchasing Restrictions
When you enter a quantity on a purchase order, blanket purchase order, purchase quote or purchase invoice line for a vendor with a purchasing restriction, an error will occur if the item is not listed in the purchasing restriction or if the entered quantity falls outside the defined range.
For all vendors, if the Verify Quantity On Release toggle is enabled on the Purchasing Restrictions Setup page, an error will occur if a purchase line has a blank quantity. To proceed, you'll need to either remove the line without a quantity or enter a quantity.