Updated Firefox browser on PC today and can no longer access my emails at https://outlook.live.com/mail/0/

I'm in it everyday with no issue. Show us something. Windows home or pro and what security software are you running besides MS Defender? Do you have the same issue with Firefox in Troubleshoot Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf Did you try clearing the browser cache? https://support.mozilla.org/en-US/kb/how-clear-firefox-cache#