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.
There was a delay on Amazon's side for processing the manifest and the items within it.
Please check the status of the feed by logging into your Amazon seller centrral account and go into your Inventory page > Add Products via Upload and click on 'Monitor Upload Status' and monitor the status of the upload in there:
For now, try to add the items directly from your Amazon seller central. You may get get a success message but the product may not be visible on your Amazon inventory.
We request you to open a case with Amazon Support.
If submitting it directly through Amazon seller central fails, then it is most certainly an invalid product setup within Amazon's catalog.