The first thing to check is whether or not the error you're seeing is a listing error. In some cases, this error gets called out directly through our listing errors dashboard, and is highlighted on the SKU level. Here's some more info about How to Manage Listing Errors.
If it's not a listing error then the next question is whether or not Zentail is sending the correct information to the marketplace. Here's a great list of places you can check:
Integration Settings - If a sync is disabled then Zentail will not send feeds to the marketplace with that information.
The List Toggle - If the List/Don't List is toggled off then Zentail is not sending information to the marketplace.
Alternate Sources of Information 1 - If the SKU is part of a product group, check the master SKU to see it's sending different information than the SKU with the issue.
Alternate Sources of Information 2 - If the SKU is an alias then the inventory is controlled by the master SKU. You can see if a SKU is an alias on the right hand side of the catalog, and what SKU it's an alias of at the bottom of the SKU card.
Alternate Sources of Information 3 - This primarily occurs on Walmart: if you have two SKUs with the same UPC Walmart is unable to tell which one is associated with an order or inventory. This can result in overselling or inaccurate inventory levels. Please be sure that there is only one SKU listed to Walmart for any given UPC.
Unique Identifiers - Check the make sure that the UPC or ASIN matches what's on the listing. This is most relevant for Walmart or Amazon where, In some cases, the information on the marketplace doesn't match your information. In other words, Amazon may find the UPC you have on a different ASIN than you expected, and put your listing there.
eBay has unique policies about editing product groups. See this article for more information.