The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.
To Reset Firefox do the following:
- Go to Firefox > Help > Troubleshooting Information.
- Click the "Reset Firefox" button.
- Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
- Firefox will open with all factory defaults applied.