Hi, I am trying to create a new listing with the new UPC and when I change the size ( somehowitbwas saved from my previous listing) it sys this:

How do I fix it?

The product details (title/bullet point/other) of your listing conflict with the product details ofanother product in Amazon's catalog. To resolve, either create an offer against the existinglisting, or update your product information and continue listing creation.The SKU conflicts with another SKU value in your inventory. To resolve, provide a uniqueSKU value.The product ID you've entered conflicts with the product ID of another item in Amazon'scatalog. To resolve, create an offer against the existing listing. If you believe that your productID does not match with the existing listing, contact support for further assistance.