We're currently experiencing a service interruption with @YouTubeTV and working to fix it! Apologies if you're unable to access or login, we'll send another update as soon as this is resolved.
Thanks for your response--yes, I use Chrome. Worked great until 3 weeks ago--now I just get a black screen with the rolling white arrow. I'm told this is an issue YouTube is aware of with MacBook pros but no fix yet. Hopefully soon? Thanks!