Please explain the problem in detail. What happens? What is/are the exact error message(s) ? What were you doing at the time? surfing, watching a clip, reading something . . . . [https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode Start Firefox using Troubleshoot(Safe) Mode] {web link} A small dialog should appear. Click '''Start In Troubleshoot(Safe) Mode''' (not Refresh). Is the problem still there?