Three minutes of ADVERTISEMENTS, before I can figure out, if I've found the correct video...
This time YouTube has done a 'take down' of some copyrighted material (likely reason, I've guessed). Video has the '!' symbol signifying that it got taken down by yt.
Any technological reason, they can't notify upfront, rather than a user experience that breeds contempt and begs for mis-trust.
Swell, then....teach your kids. (That's my snark, sorrrry).