I'm not Help or Support, but I think your computer is mesing up, like not geting the info it needs to show the video. Did you move (to a diffrent house) lattly? If so that's probly why it's messing up.
Chess.com Videos not working

Thankyou for the reply spots100.
I figured out what it was. My Cache needed emptying (The help files).
CONTROL+F5 when on a page clears the cache.
Hello Help and Support.
I cannot view any videos. All i get is a black screen. It was working fine a few days ao.
Thanks.
PJK.
EDIT :: Pressing CONTROL + F5 whilst on the page i was trying to view has solved the problem. It seems my cache needed clearing.