Good question. Will give the articles (at bottom) but since have taken that apart it might be best to file a bug report. https://bugzilla.mozilla.org/ Bug Writing Guidelines : https://developer.mozilla.org/en-US/docs/Mozilla/QA/Bug_writing_guidelines 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) and test. Is the problem still there? To submit suggestions for new or changed features, may I suggest: Feedback: https://qsurvey.mozilla.com/s3/FirefoxInput/ https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues . https://support.mozilla.org/en-US/kb/fix-video-audio-problems-firefox-windows . https://support.mozilla.org/en-US/kb/html5-audio-and-video-firefox Please let us know if this solved your issue or if need further assistance.