Looks like the Windows Media Player MP4 bug is back, for some people at least. If you are having difficulty playing some video files (typically they play the audio but black instead of the picture) on windows media player, try downloading VLC player here:
This seems to solve the problem.
I’ve no idea why WMP won’t play some of the files- they’re all made exactly the same way on my Mac, and Quicktime player and VLC seem to be able to play them fine. So I believe it is a bug in WMP.
A little bit of a Google indicates that other set-ups can cause WMP to do this- a lot of GoPro users complaining about it a couple of years ago, for example. Installing fresh MP4 codecs might fix it. A member has tried transcoding with ACDSee, and the transcoded versions play fine- but that again implies that there’s nothing wrong with the original, as the transcoding software can process it just fine. So it genuinely looks like a Microsoft WMP bug that they don’t seem to be in a hurry to fix. Download VLC 🙂