If you are encountering the error message "Video can't be played because the file is corrupt" in a specific application or media player while the same video works fine in other players like Chrome, Edge, and VLC media player, the issue is likely related to the specific media player's settings or compatibility. Here are some troubleshooting steps to address the problem:

Update or Reinstall the Media Player: Ensure that you are using the latest version of the media player experiencing the issue. Check for updates or consider reinstalling the player to fix any potential bugs or corrupted files in the application itself.

Clear Cache and Temporary Files: Clear the cache and temporary files of the media player to eliminate any conflicting or corrupted data that might be causing playback issues. You can usually find this option in the settings or preferences menu of the media player.

Update Graphics Drivers: Outdated or corrupted graphics drivers can sometimes cause video playback problems. Update your graphics drivers to the latest version compatible with your operating system.

Check File Format and Codec: Confirm that the video file format and codec are supported by the problematic media player. Some players may have limited codec support, leading to playback issues. In that case, consider converting the video to a different format or installing additional codec packs.

The media player is internal part of Firefox as far as I know and can not be reinstalled separately. I tried both anonymous window, and "troubleshooting mode", both did have same result, so I assumed it is Firefox issue, because it was reported to me, that the video does not work, so I tried it, and it did not work for me with Firefox either, so I reported it.

The video is using YUV444 chroma subsampling which is not supported (Bug 1792396).