Is anyone else encountering this? It happens only with Firefox when going to any youtube user home page; a big black square blocks off most of the page; below is an example, using the sample search word 'wind', but it happens no matter what search word or user name I use:
I right-clicked on the big black square, and chose adblock, 'block image', and the black square disappeared and gave me back a normal yt screen.
update: Hmm, nope, still there, my mistake; it thought I was choosing a video and took me to it, was all that happened. If I go to any yt index of videos, the black square still appears.