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No video support and MIME type found

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After the recent bunch of windows updates i started noticing youtube loading much slower and other websites acting strange. Just now i tried to look at a link https://steamusercontent-a.akamaihd.net/ugc/47948470127416586/912CDEE3AD8B94CF3122B7338E89E24C9B6EC29D/

I get "No video support and MIME type found". I have uninstall/reinstalled, checked codex, disabled addons and downloaded Microsoft windows media pack, then restarted the computer.

Nothing seems to work. But i had to reinstall Firefox again because all my tabs would crash after the last reinstall.

After the recent bunch of windows updates i started noticing youtube loading much slower and other websites acting strange. Just now i tried to look at a link https://steamusercontent-a.akamaihd.net/ugc/47948470127416586/912CDEE3AD8B94CF3122B7338E89E24C9B6EC29D/ I get "No video support and MIME type found". I have uninstall/reinstalled, checked codex, disabled addons and downloaded Microsoft windows media pack, then restarted the computer. Nothing seems to work. But i had to reinstall Firefox again because all my tabs would crash after the last reinstall.
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I have a copy of the old YouTube HTML5 support page you can use as the first-level test of where video support is falling short:

https://www.jeffersonscher.com/sumo/html5-video.html

The expected result is: supported, probably, probably, supported, supported, supported

If yours doesn't match, which ones are a problem?

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jscher2000 - Support Volunteer said

I have a copy of the old YouTube HTML5 support page you can use as the first-level test of where video support is falling short: https://www.jeffersonscher.com/sumo/html5-video.html The expected result is: supported, probably, probably, supported, supported, supported If yours doesn't match, which ones are a problem?

spp / sss I am not sure what to do with this information.

I also got errors when updating this reply. This stuff has only started happening recently and only noticed after a bunch of pc updates, am wondering if Firefox is being crushed by competition.

由 Griswald 於 修改

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When i closed this browser today the Desktop shortcut and my Taskbar icon were deleted aswell, something really fishy is going on with this browser.

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That sounds a bit suspicious. In case Firefox's program files became corrupted, could you re-run the full installer? It should do an in-place update (no need to uninstall first):

https://www.mozilla.org/firefox/all/desktop-release/

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Any more information available in the Web Console?

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jscher2000 - Support Volunteer said

That sounds a bit suspicious. In case Firefox's program files became corrupted, could you re-run the full installer? It should do an in-place update (no need to uninstall first): https://www.mozilla.org/firefox/all/desktop-release/

I will give that a go and see if things improve. Again it has only happened recently since a bunch of windows updates. I have not had to update Firefox during this stuff, but if i open google chrome it's always got new updates.

My original issue of why im here still remains. And looking through other posts i see other people are getting similar issues with format issues and MIME.

由 Griswald 於 修改

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cor-el said

Any more information available in the Web Console?

Mostly just this stuff. (screenshots)

由 Griswald 於 修改

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I'll assume by the amount of other threads with similar problems.. that this is a forever issue with Firefox and windows and google are working to cause issues so they can get all their ad money without competition.

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The problems still persists.

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If you haven't already, could you test in Firefox's Troubleshoot Mode? In that mode, Firefox temporarily deactivates extensions, hardware acceleration, any userChrome.css/userContent.css files, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is running:

You can restart Firefox in Troubleshoot Mode using either:

  • "3-bar" menu button > Help > Troubleshoot Mode...
  • (menu bar) Help menu > Troubleshoot Mode...

and OK the restart. A small dialog should appear. Click the Open button.

If Firefox is not running:

Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.) A small dialog should appear. Click the Open button.

Note: Don't use the Refresh without first reviewing this article to understand what will be deleted: Refresh Firefox - reset add-ons and settings.

Any improvement in stability (not sure it would improve video compatibility)?

Ref. Use Troubleshoot Mode in Firefox