Revising or Relisting Items won't take UPC Number

[stlhardware]

Good morning - I have been trying to add UPC numbers to my listing by revising, relisting, or sell similar and when I do a little warning/error flag comes up saying it is not correct or not in the product catalog - some of the items are old but some are not and these UPC codes are what are on the original packaging - see item: 391163119771 - do I enter the UPC no matter the warning/error flag or do I just not enter one at all.  Thanks in advance for all your help.