Error 17: You cannot access the item because the listing may have been cancelled or you are not the seller.

This error indicates an item cannot be accessed. This may be because the listing has been canceled, the item is not activated, it is no longer in the database, or it is a Live Auction item. To avoid this error: check for removal notification (the seller should receive an email from eBay) in your application, filter inactive items that are over 30 days old using the EndTime field in the response of a GetItem call, verify the item ID, check server URL (production or sandbox), and check that the marketplace is applicable for the item ID.