You can try to disable DNS over HTTPS. *https://support.mozilla.org/en-US/kb/firefox-dns-over-https *https://support.mozilla.org/en-US/kb/dns-over-https-doh-faqs You can check the connection settings and check for possible issues with a Proxy or VPN service. *Settings -> General -> Network: Connection -> Settings If you do not need to use a Proxy to connect to internet, select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly. See also: *https://support.mozilla.org/en-US/kb/connection-settings-firefox *https://support.mozilla.org/en-US/kb/websites-dont-load-troubleshoot-and-fix-errors See also: *https://appuals.com/pr-end-of-file-error/