@TeamYouTube not entirely sure if anybody else has mentioned it but the Xbox One app keeps crashing. Whatever video I am watching freezes about halfway through and then I get an error message saying YouTube is unavailable before the app crashes entirely. Just a heads up.
There are currently technical issues in the Xbox firmware that's causing these issues. Microsoft is investigating. In the meantime, if it happens again, you can try uninstalling & reinstalling the app to see if that works!