For example, some remixes were stored by the YouTube channel "Hardwave Uploadz". Apparently, they got many remixes from the social network "VKontakte", uploaded them on YouTube, unlisted them at some point, and it all seemed fine. But then, this happened:
I think you used a URL with a timestamp to embed that video. It starts at 55 seconds, where it says that "Unlisted videos uploaded on or after January 1, 2017 will not be affected," so I had to manually go to the beginning of the video to see what what happening to unlisted videos uploaded before January 1, 2017.