QuickTime plays most of the MP4 videos with MPEG2, MPEG-4, H.264, and so on.

If none of the above methods have worked out then the next thing to do is to convert MP4 file to QuickTime supported format.

Convert MP4 to QuickTime Supported Format:.

You can try playing the video on VLC player or MPlayerX when you experience QuickTime MP4 playback problems on macOS High Sierra. The next solution is to try to play the MP4 video on an alternate media player.

So you need to download the required codecs to play the MP4 video on your macOS High Sierra. Sometimes when the required codec is not present in QuickTime, there are chances of the MP4 file not playing. So, get QuickTime 7 Pro or any higher version on your MacOS High Sierra and play MP4 files. And, QuickTime 7 Pro is the best one to deal with. This is because QuickTime 7 and above can handle MP4 files better. If you have corrupt or damaged videos shot on iPhone, you can know how to repair corrupt iPhone video here. Listed here are a few solutions to playback problems with QuickTime MP4 file on macOS High Sierra. Well, you don't have to worry as there is a solution to every problem. The MP4 file has playback problems on QuickTime. After that, there have been issues with MP4 video.

On one such occasion, you had upgraded to the latest macOS High Sierra version. But the situation turns annoying when you don’t know how to fix the issue and get back to playing the video. Problems while playing video files is common.

Free quicktime for mac 2018 high sierra