The long error message is "You will be unable to complete this request until payment is made or a credit card is put on file for automatic monthly billing." eBay places limits on the amount of listing that can take place without an active credit card or bank account on file. Once this limit is reached, any AddItem, RelistItem or AddSecondChanceOffer calls will fail. More information can be found in this eBay.com help page: https://www.ebay.com/help/home.