Hello Tomsl and billyboy55.
I am happy to assist you with this today.
There are a couple possibilities to this error.
1.) eBay’s servers are having temporary issues.
2.) When you view your listing profile, find the “Upload to EPS” setting and check what it is set to. eBay requires gallery images to be uploaded to EPS so EPS needs to be enabled in the listing profile. In order to fix this you should change the setting to “Upload All Images” or “Upload First 12 Images”. After that, make sure your listing(s) are unlocked, and run a revision on the listing. Please note though, only the Pro version of WP-Lister will upload gallery images to eBay. eBay uses their EPS servers (eBay picture service) to host all of their gallery images, and only WP-Lister Pro can upload images to EPS.
If you already have the settings in #2 set that I mentioned (and you are using Pro not Lite), and you have waited ~24 hours (in case it is a temporary eBay issue) and you are still having issues, please provide me with your dashboard URL, admin login/password, and a sample SKU for a product throwing this error but not on the forum, please send this information in a ticket here: https://www.wplab.com/request-support/
Kind regards
John