You appea5 to be using the Firefox 63 beta version and not the current release. You can check the update channel in "Help -> About Firefox". Firefox 63 is scheduled to be released next week, so Firefox 62.0.3 is still the current release. *https://www.mozilla.org/en-US/firefox/all/ You can check if you have an "Old Firefox Data" folder on the desktop in case the Refresh feature in Firefox has been used and a new profile has been created. *https://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-most-problems *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile *https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them ---- It is possible that your firewall or other security software blocks or restricts Firefox without informing you, possibly after detecting changes (update) to the Firefox application. Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access for Firefox and the plugin-container process and the updater process. See: *https://support.mozilla.org/en-US/kb/server-not-found-connection-problem *https://support.mozilla.org/en-US/kb/Firewalls *https://support.mozilla.org/en-US/kb/fix-problems-connecting-websites-after-updating