Video doesn't show in Firefox or Chrome

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1

I just wrote this post, which includes a 2-minute video:

When I look at the post on Safari, the video shows up and plays normally. When I look at the same page in Chrome or Firefox, the video is grey and you can only hear the audio. Why is this?

2

Sounds like this maybe? MP4 files won't work in Firefox | Firefox Support Forum | Mozilla Support

Are you on Windows?

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Oh! Wow, nope, not on windows. I’m using Mac OS 14.6.1. Weird! I’m not sure what I do about that? Handbrake doesn’t list MP3 or whatever (I don’t know my formats so I’m guessing). Thanks for figuring this out! Helps to know it isn’t something I’m doing on my end.