What does the error "Attachment not found in digital product" mean?
The "Attachment not found in digital product" error occurs when you are trying to list a digital product on Etsy but haven't attached the required downloadable file. For a digital product to be listed on Etsy, you must provide an attachment (such as a file for download) that meets Etsy's file size and format requirements (not larger than 5 MB).
If you're not listing a digital product, go to your Shopify store, uncheck the "This is a physical product" box, and save the product. This will remove the digital product designation and resolve the error.