The Error:
This SKU is not in the Amazon catalog. If you are receiving this message after submitting a multi-marketplace inventory file and the designated marketplace for this error is different than the marketplace in which you submitted your file, this error is an indication that the Detail page for this item does not exist in the designated marketplace. Amazon is attempting to create the Detail Page for this item on your behalf. If successful, your listing will be created in the designated marketplace within 48 hours.
Why?
This issue "not in catalog" occurs when the Inventory listing does not exist in Seller Central. It may also happen when an item is listed in ScanPower and listings have not been created yet via Product and Inventory feeds which are sent when you "Create Listings."
Finally, this may happen when you Send Contents in PREP & SHIP and the carton feed is processed before the listings are created.
What should you do?
Typically, using the Create Listings function in PREP & SHIP will resolve this problem and prevent the items from going stranded.
Check the feed status by navigating to: https://unity.scanpower.com/list/feed
If the feeds are processed successfully you should see the inventory in Seller Central.
If there are Product feed errors you can add the Inventory directly in Seller Central.