Can you show us what you get when trying to get to youtube.com Have you tried Firefox in Safe Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf Clear the browser cache. https://support.mozilla.org/en-US/kb/how-clear-firefox-cache Also try downloading Firefox from Mozilla, run '''firefox-bin''' from the folder and see if you have the same issue. https://www.mozilla.org/en-US/firefox/all/#product-desktop-release