: If the video has sound but no picture (or won't play at all), you may need to install a codec pack like the K-Lite Codec Pack to help your player understand the file's compression. What is an MP4?

: Most modern operating systems like Windows and macOS will automatically open MP4 files using default apps like Windows Media Player or QuickTime.

For a quick guide on how to create and open these files on your computer, check out this tutorial: How to Create and Open an MP4 File YouTube• Nov 2, 2016

If you are trying to view this specific file or any other MP4 on your device:

The reference to feature: 2119702874761.mp4 appears to relate to the game , where players have discovered they can manipulate game files—specifically by replacing or interacting with video files like the "feature presentation". How to Open or Use MP4 Files