Full Error Message:
Miscellaneous error, click for more details
An error was found for which more information is not available.
Click More Details below for the specific details returned from eBay UK.
For help resolving this error please view the following help guide.
Error: Item can’t be accessed.; This item cannot be accessed because the listing has been deleted or you are not the seller.
Problem:
ChannelUnity is trying to update a listing on eBay but the listing has already been ended/removed from eBay
Solution:
Delete and purge the listing in ChannelUnity which will send a delete request to eBay to remove the listing it’s trying to update, wait 20 minutes, and then upload the product to create a new listing on eBay (note: the old listing will be deleted from eBay with all it’s history).