This seems to come in the wake of the "test" I participated in, along with all the changes. I have received an email saying Etsy's engineers are working on it, but it severely hamstrings listings.
It happened to me yesterday when I edited an existing list with new photos and video. It told me I had 1 photo that wasn't saved and I tried to publish edits numerous times. My workaround was, I deleted the new video and reloaded it. Then it published.
