Right-click the file and remove the extra .mp4 so the name ends simply in .mp4 .
Because the filename follows a standard timestamp or archival format (Live + Year + ID), 1. Check the Source
If you downloaded this from a forum or P2P site, it may be a clip of a live performance or broadcast. 2. How to Open the File
If you are having trouble playing the .mp4.mp4 (which looks like a double extension error), try these steps: