Open it with a universal player like VLC Media Player if your default player won't open it.
What do you want? (e.g., funny, professional, inspiring) Information optics: How to view video metadata - Canto 0gmwb6j4kl1ghx4opv2eh_source.mp4
The filename appears to be a system-generated or temporary identifier rather than a known viral video or specific piece of public content. Open it with a universal player like VLC