“Videos are not available on this platform” error message
I can't view my own videos on mobile devices
If your video has been claimed by a copyright owner, the owner may have chosen to restrict the video from being shown on certain devices (mobile phones/tablets, Smart TVs, and game consoles).
I can't view other people's videos on mobile devices
YouTube’s distribution model allows monetizing partners to control the platforms on which content is available. For more information please view Common Questions about Distribution Settings.