Frequently Asked Question:
I received an API error when I tried to relist. What does it mean?
If you tried to relist an item that is older than 90 days, you may receive an API error message that says: "This item cannot be accessed because the listing has been deleted, is a Half.com listing, or you are not the seller."
EBay only keeps a listing on file for 90 days, so when you try to "relist" an item, their system will not have a record of the original listing, thus the reason for the error message.
To relist the item, you will need to find the original Saved listing you used to list it onto eBay and launch it again, or create a whole new listing.