[https://support.mozilla.org/en-US/kb/install-older-version-of-firefox?cache=no Install Older Version Of Firefox] {web link} 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]

Quantum is the next Firefox 57 release and is currently Beta. You can install the current Firefox 56.0.1 release if you do not want to keep using the Beta version. You need to install the full version of the current release. *https://www.mozilla.org/en-US/firefox/all/ Keep in mind that your profile might be getting corrupted if you revert to a previous version.