This type of error is returned by eBay when the product condition submitted is not compatible with the mapped category.

The module automatically sends the condition New or Used to eBay, reading it from the Prestashop product condition. However, some eBay categories (especially books, media, trading cards and video games) require specific conditions, such as “Acceptable,” “In good condition,” or similar.

These types of conditions can be mapped from the “Specifications and Conditions” tab of the module, by deactivating the use of default conditions and mapping the conditions expected by Prestashop with those proposed by eBay.

(See the relevant section in the documentation for more details).