This error is caused by a problem with Firefox program files. The solution is to remove the Firefox program and then reinstall Firefox. (This will not remove your passwords, bookmarks or other user data and settings which are stored in a separate profiles folder.) Uninstall Firefox.
How do I fix Firefox not opening?
- Restart your computer. Sometimes problems can be fixed by simply restarting your computer and then starting Firefox again.
- Clear your cookies and cache. ...
- Restart Firefox in Safe Mode. ...
- Restart Firefox in Troubleshoot Mode. ...
- Reinstall Firefox. ...
- Refresh Firefox. ...
- Create a new Firefox profile.
How do I reset Firefox browser?
Reset Firefox back to its default settings on Windows computer.
- Click the menu icon, then click on “Help”. ...
- Click “More troubleshooting information”. ...
- Click the “Refresh Firefox” button in the upper-right corner of the “Troubleshooting Information” page.
