If the Auction lots are the Etsy lots, then use the Find and just Auction lots but leave the field blank.
Meaning go to Find. And click on Auction Id but leave the auction id field empty ,, Click Find First.. Any auction lot that doesn't have an ID in it will appear as you click Find First
Just add a value in the Auctoin id field
Sometimes I add the item id number from the site such as Bonanza's item number.. Just copy/paste the number in .. or add the date the item was listed on the site. Any number in that field will stop the error happening
I figured it out just a couple days ago. In Grid View, it was very obvious where the empty cells were, and they were all Etsy items where, after listing something, I'd simply forgotten to paste the item ID number into the Auction ID boxes. Just another reason to wish AW would add support for Etsy.