Hyper on my Surface has stopped working properly also, subscriptions aren't loading and other bugs. Any news on this? YouTube is crucial to my tablet usage.
Update: I've just uninstalled and reinstalled Hyper and it seems to be working now.
Yeah I'm getting this within metro apps on Windows 8.1 Consumer Preview too - what's the bet Google just decided to pull the plug on YouTube just like they did on WP.... -.-