Click Advanced and then check 'Show Develop menu in menu bar'.

Then, you can play videos on your Mac as usual. If this issue doesn't cause by the problematic network, you can follow the solutions below to do troubleshooting. Sometimes, the unstable or poor network connection will lead to the videos not playing on Mac. If you can't play a YouTube or other online video in Safari, Chrome, or other browsers, you can check your internet connection first. How to fix online videos not playing on MacBook? Local/downloaded videos not playing on Mac, what to do?

Why won't your Mac play videos? If you can't find a clue and don't know what you should do to make the video playable again, you can follow this tutorial that aims to help you fix the videos not playing on the MacBook issue. Or, you are preparing to play a downloaded video but fail. You feel excited to watch the NBA games, live gaming, movies, or YouTube tutorials on your Mac, like MacBook or iMac, but only to find that the video won't play. MacBook Not Playing YouTube or Downloaded Videos, What to Do

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