SKYWALLThe channel isn't live right now
Live streams start and end on the broadcaster's schedule, and 24/7 channels sometimes restart under a new address, which ends the old one. Check the channel's Live tab on YouTube, or see which news channels are live right now.
It plays only in some countries
Broadcasters can limit a stream to some countries, often because of rights to sports, films or shows. YouTube then says the video isn't available in your country.
Its owner blocks playback on other sites
A channel can stop its videos from playing outside YouTube. In an app or website that uses YouTube's player, the player then says the video is unavailable and that playback on other websites has been disabled by the video owner. The stream still plays on YouTube itself.
It's age-restricted
Age-restricted videos play only on YouTube, for signed-in viewers old enough to watch them, and not in other sites' players.
The network
School, office and public Wi-Fi networks sometimes block YouTube. A slow connection makes a live stream stop to buffer, and several streams at once need more speed; see how much speed several streams take.
In Skywall
Skywall plays only broadcasters' streams that allow playback in apps, and checks every hour which channels are live. When a screen says its channel isn't live, the broadcaster isn't streaming right now; the channel comes back on its own when it does.
Questions
What does error 150 mean on YouTube?
The video's owner doesn't allow it to play in embedded players, so it plays only on YouTube itself. Error 101 means the same.
What does error 153 mean?
The page or app that embeds YouTube's player didn't identify itself to YouTube, usually because the HTTP Referer header is missing. It's for the site's developers to fix.
Why does a 24/7 news stream suddenly end?
Broadcasters restart long streams from time to time. The new stream gets a new address, and links to the old one show that the live stream has ended.