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Unable to watch YouTube videos with Firefox

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  • 3 have this problem
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  • Last reply by FredMcD

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We are unable to watch any YouTube videos with Firefox. I've added and removed Flash plugins, added and removed HTML5 (several different plugins for it), deleted all history and cookies, started in safe mode, uninstalled and reinstalled, and basically did every other troubleshooting issue I could (aside from DNS because we use corporate DNS). We are unable to show training videos and other work related videos in a corporate environment. We either get the message 'an error has occurred' or 'no video with supported format and MIME type found'. When you first load up YouTube, the featured video at the top of the page comes up as 'secure connection failed'. You can't load the site at all without https, so that wasn't an option to try. Our Flash is updated to the most recent version, so there shouldn't be a security issue there. YouTube is allowed through our firewall. Any help would be appreciated.

We are unable to watch any YouTube videos with Firefox. I've added and removed Flash plugins, added and removed HTML5 (several different plugins for it), deleted all history and cookies, started in safe mode, uninstalled and reinstalled, and basically did every other troubleshooting issue I could (aside from DNS because we use corporate DNS). We are unable to show training videos and other work related videos in a corporate environment. We either get the message 'an error has occurred' or 'no video with supported format and MIME type found'. When you first load up YouTube, the featured video at the top of the page comes up as 'secure connection failed'. You can't load the site at all without https, so that wasn't an option to try. Our Flash is updated to the most recent version, so there shouldn't be a security issue there. YouTube is allowed through our firewall. Any help would be appreciated.

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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?


There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate.

http://www.ehow.com/how_11385212_troubleshoot-reset-connection-firefox.html

https://support.mozilla.org/en-US/kb/server-not-found-connection-problem

https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites

https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message

https://support.mozilla.org/en-US/kb/connection-untrusted-error-message

http://kb.mozillazine.org/Error_loading_websites

https://www.bing.com/search?q=web+site+access+denied

https://support.mozilla.org/kb/troubleshoot-SEC_ERROR_UNKNOWN_ISSUER

This Connection is Untrusted is sometimes caused because the computer system clock is wrong. Check the time / date / time zone settings.