Thanks for contributing to our forum. We actually just saw this particular error come up in a couple accounts over the past week, so it appears that eBay just implemented a new policy preventing eBay UK sellers from using third party listings tools before they have feedback scores of at least 10 and 90 days have gone by since their first sale.
While your Auctiva account is already configured to automatically add the scrolling gallery to your listings, the API error message that eBay returned in response to your recent posting attempts suggests that you will also be unable to revise your listings through third party listing tools for the time being, so I suspect our attempts to add the scrolling galleries to your listings will be rejected by eBay as well.
However, in the event that we are unable to add the scrolling galleries to your listings automatically, you should still be able to get the HTML code used to generate the scrolling gallery from within your Auctiva account and then incorporating that code into your description HTML when listing and/or revising your items directly through eBay.
You can obtain your scrolling gallery HTML code by mousing over the “Stores” tab within your Auctiva account and then selecting the “Get HTML” option in the “Scrolling Gallery” section.
I hope this helps. If you need any further assistance with your account, please feel free to contact our customer support team by mousing over the “Help” tab within your account and then selecting the “File Support Case” option.