This article may help. https://support.mozilla.org/en-US/kb/fix-video-audio-problems-firefox-windows Try clearing cookies and site data and clearing the cache. https://support.mozilla.org/en-US/kb/clear-cookies-and-site-data-firefox https://support.mozilla.org/en-US/kb/how-clear-firefox-cache The problem could be caused by something in your profile (such as an add-on or a setting). A quick way of testing is to create a new profile. https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems (also deals with hardware acceleration)

Thanks for the reply. I tried all the above but it is still there. I am so confused...