Yikes! Are you using an Android/iOS? Also, please check if it's this the same when you switched network from WiFi to mobile data and vice versa. Keep us posted.
@TeamYouTube @YouTube
When I try and watch a video it won’t work on my phone. I open it and it just buffers forever. It’s not my WiFi or my phone. Other apps work (video wise). Please fix or send me a fix. 

-
-
-
This Tweet is unavailable.
- 1 more reply
New conversation -
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.