This item can't be accessed because the listing has been deleted, or you're not the seller

This error normally appears if you try to relist/revise item which had been stopped more than 60 days ago. eBay removes all items from its system after 60 days because of non-activity.  So you should use List action to make an item active on eBay first.

The error may also appear if you change eBay account in the Listing, i.e. item was listed with one eBay account, then you change account and try to perform the activity using another eBay account.