'''Note: ''' v55 has been giving users problems. Reinstall v54. https://support.mozilla.org/en-US/kb/install-older-version-of-firefox?cache=no Be sure to read everything here. If you still want to downgrade, look under; I still want to downgrade. Click the Directory of other versions and languages link. Look for the directory of the version that you want. But, remember that old versions may have security issues. You should also check out [https://www.mozilla.org/en-US/firefox/organizations/ Firefox; Extended Support Release] {web link} [https://www.mozilla.org/en-US/firefox/organizations/notes/ ESR Notes] [https://www.mozilla.org/en-US/firefox/organizations/system-requirements/ System Requirements] ---------------- Crash reports. If you can't get Firefox to open, you will have to do this the hard way. '''https://support.mozilla.org/en-US/kb/mozillacrashreporter''' Open the file browser / explorer on your computer. '''Note:''' You may have to enable '''Show Hidden''' '''Folders / Files.''' Enter this in the address bar; '''Windows:''' %APPDATA%\Mozilla\Firefox\Crash Reports\submitted '''Win 7/Vista:''' C:\Users\'''<username>'''\AppData\Roaming\Mozilla\Firefox\Crash Reports\submitted '''Win XP/2000:''' C:\Documents and Settings\'''<username>'''\Application Data\Mozilla\Firefox\Crash Reports\submitted '''Mac OS:''' /Users/'''<username>'''/Library/Application Support/Firefox/Crash Reports/submitted '''Linux:''' /home/'''<username>'''/.mozilla/firefox/Crash Reports/submitted Copy the most recent '''5-7 File Names''' in the folder. Post the information in the reply box.

Try to start Firefox in <u>Safe Mode</u> to see whether that works. *Windows: hold down the Shift key while starting Firefox *Mac: hold down the Options key while starting Firefox