I have also been affected by this issue, with 3 listings failing over 2 nights. I have spoken with 4 different customer support staff and got very different responses. Got this escalated to two supervisors, and also got the response that this is a known eBay glitch.
In my latest response from eBay Support I got directed to the following article: http://sellercentre.ebay.com.au/news/sp16/structured-data
I have asked for clarification on this for my situation because I have also got advice to make sure the UPC is filled in (in my case with "Does not apply"). However there is no mention of UPC in this article. My current guess is that I need to revise my listings with Brand = Unbranded, which in turn will generate something called an eBay Product Identifier, which in turn is considered a valid product identifier and will allow relists to go through successfully.
I use InkFrog (3rd party software) to launch and revise listings. Interestingly this evening I have found that the UPC field has been removed from Multi variation listings in the InkFrog lister. I have raised a support request InkFrog to understand what's going on here, but all of this suggests something is clearly up with UPC and Product Identifiers, and unfortunately we are all caught up in this.
I have also been advised by eBay that whatever new rules they are implementing, are temporarily being placed on hold whilst this issue is being resolved. Hopefully that will stop further relists failing until we get more clarity.
I'm interested in others interpretation of the article in the link above.
Wish everyone the best.
