Why isn't my video working on my Mac?
Possible root causes could be malware or virus issues, file damage, network interruption while downloading the file, issues caused by wrong video processing, and your player not supporting the file format. All of these are common and possible reasons for videos not playing on Mac.
Why is video black on Mac?
If your screen goes black, your Mac or display may have gone to sleep. If you have a Mac laptop, it may be out of power.
Why doesn't MP4 play on Mac?
You cannot play MP4 on Mac, if the codecs used in your video file are missing. Issues like QuickTime player has no sound on Mac when playing MP4 file or audio lag are usually due to incompatible codecs. So download MP4 codecs on Mac to fix the issue.