This is a generic error issued by eBay during synchronization.
The inability to publish the item does not stem from a direct problem with the module, but from a limitation on one’s own eBay account that prevents the listing from being published.
This message is often returned in the case of seller accounts that are limited or blocked from selling, with incomplete information or subject to eBay restrictions.
In rare cases, the error appears when the listing is not allowed due to invalid words or product categories not sellable on the platform.
If you receive this error following a massive manual synchronization (launched from the SYNC menu), the error might appear incomplete and you might not understand the reason.
To quickly see the extended error message issued by eBay, you can use the “Fastbay Sync” button to start the synchronization from the product tab of a site of an impacted product (button to be activated in the general module configurations if not present) or consult the eBay response through debug mode as described in a dedicated FAQ.