This error occurs when you fast list a product and try to connect to an incorrect ASIN on Amazon. Connecting to the incorrect ASINs may lead to data conflicts and failed creation of your product.
Solution:
You can solve this issue by finding the correct ASIN from Amazon and updating the current ASIN. After that you need to “Delete & Recreate” this product, after enabling fast listing.
You need to remove the ASIN override and try to create this product with a valid product identifier and type.
1- Click edit to product and delete the asin override from product id override column and select the correct product id type regarding to your actual product id(UPCs are 12 digits e.g).
2- Select the product, send product data update and sync the channel.