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why getting "This video format is not supported" error message while trying to play mp4 files?

  • 6 replies
  • 1 has this problem
  • Last reply by James

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I am using the latest version of firefox. with default settings. having issue with mp4 videos which sent to me by email or shared on google drive. I can not play those mp4 files. the error message is : "This video format is not supported" and a black screen.

please help.


All Replies (6)

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Let's start with this;

Separate Security Issue: Update your Flash Player or remove it using these links; Uninstall Flash Player | Windows Uninstall Flash Player | Mac

Note: Windows users should download the ActiveX for Internet Explorer. and the plugin for Plugin-based browsers (like Firefox).

Note: Windows 8 and Windows 10 have built-in flash players and Adobe will cause a conflict. Install the plugin only. Not the ActiveX.

Flash Player Version: Version Direct link scans current system and browser Note: Other software is offered in the download. <Windows Only> Step 1: Select Operating System Step 2: Select A Version (Firefox, Win IE . . . .) Note: Other software is offered in the download. <Windows Only> +++++++++++++++++++ See if there are updates for your graphics drivers

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Please provide public link(s) (no password) that we can check out. No Personal Information Please !

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Wow. A motorcycle that drives itself.

I trust you updated your flash. Is there still a problem?

Make sure you are not blocking content.

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

One issue that seems more common lately is Firefox's Tracking Protection feature. When it is blocking content in a page, a shield icon will appear at the left end of the address bar next to the padlock icon. This article has more info on managing this feature: Tracking Protection {web link}

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first of all I tried on different computers, same result. graphic driver is updated as you said. flash player is updated. and also tried in same mode, to no success! So you watched the video meaning that it works for you. Does this problem have a relation with version of operating system? the machines I used, both have win 10.

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The video is HTML5 and not using Flash Player Plugin.

You can see what your system supports at as all check marks should be blue.

If you have a N or KN edition of Windows that you may not have the media feature packs which provides the necessary codecs.