You send your feed by sending the offers (synchronization), in the report you get an error , like this one:
Message: 1 Error 8560: SKU: XXX-YYY, Missing Attributes product_type. SKU XXX-YYY does not match any ASIN. Creation of a new ASIN requires the following missing attributes: product_type. Feed ID: 0. For details, see http://sellercentral.amazon.es/gp/errorcode/200692370
The module has two modes, sending offers (Synchronization) to synchronize inventory and sending products (Creation) to create a non-existent product.
When sending offers (synchronization), the offers are sent in matching mode, i.e. the product will update your stock if the offer exists and if it does not exist the module will try to create an offer on the basis of an identical product that might exist on Amazon.
However, if the product does not exist, you get this error message in the report.
The procedure to follow is then to create the non-existent product on Amazon by sending the products (Creation). Follow the steps for Sending Product Feed (Creation).