Hey there! Type about:preferences#advanced<Enter> in the address bar. Under Advanced, Select Network. Look for Configure How Firefox Connects and press the Settings button. If you are using a proxy, make sure those settings are correct. If there is no proxy, first use No Proxy. If there is a problem, then try System Proxy. Some problems occurs when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again; Make sure your Internet security software is up-to-date (i.e. you are running the latest version). Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see https://support.mozilla.org/en-US/kb/configure-firewalls-so-firefox-can-access-internet Hope I helped! Kind regards, Bithiah