Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Recently whenever I download MP4 videos from Youtube, it does not work on my PC. The FLV videos are working just fine.

  • 1 phendula
  • 36 inale ngxaki
  • 20 views
  • Impendulo yokugqibela ngu Microrobot

more options

Recently whenever I download MP4 videos from Youtube, it does not work on my PC. The FLV videos are working just fine. Point to be noted that previously downloaded MP4 Videos from youtube are working just fine.

Recently whenever I download MP4 videos from Youtube, it does not work on my PC. The FLV videos are working just fine. Point to be noted that previously downloaded MP4 Videos from youtube are working just fine.

All Replies (1)

more options

Hello,

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

  1. Go to Firefox > Help > Troubleshooting Information.
  2. Click the "Reset Firefox" button.
  3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
  4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

Thank you.