You can send the information in the POST_PRODUCT_DATA feed first, but good luck on having it work. I have had a ticket open with Seller Support for over a month and, even though the information sends through that product feed and shows up on Amazon for the item, the error still kicks back.
Amazon’s response from their development team is that the MSKU isn’t on all of the marketplaces for AMAZON_NA, so even though US has the product data from the product feed, the other marketplaces don’t, resulting in the error.
Some sellers will run into this error and some won’t for the same exact product, sent the same exact way, so I am not convinced of their response.
I will be very interested to know how you get around this if you do since you seem to be one of the (un)lucky ones running into the error. It has driven me nuts for a very long time!