Are you seeing this error message on your eBay listings in WholeCell? This means the listing will end immediately when you run out of stock, and WholeCell will display 'Ended' on the listing table. Due to this, it will be unable to update the quantity when you add inventory for that listing.

If the Out-of-Stock feature is enabled in eBay, your listing will not end even if you run out of inventory.

To enable this in eBay, go to My eBay > Account > Selling Preferences and turn on "Listings stay active when you're out of stock."