Error:  Relist Items: Success
ebayid:82 Failure | ErrorCode:37 
ShortMessage:Input data is invalid. 
LongMessage:Input data for tag <Item.PictureDetails.GalleryURL> is invalid or missing. Please check API documentation.
Item.PictureDetails.GalleryURL


Solution:  


Go to Settings > Selling >  eBay Options 


Change Use Default Image for Variations to ON