I got in Firefox: This address is restricted This address uses a network port which is normally used for purposes other than Web browsing. Firefox has cancele

I got in Firefox: This address is restricted This address uses a network port which is normally used for purposes other than Web browsing. Firefox has canceled the request for your protection. It wouldn't even try to connect until I set network.security.ports.banned.override to "8123" in about:config. But now that I've set it, it seems that the website is unresponsive (overloaded?) anyway.