I am trying to get to a specific port and Firefox blocks the access, https://x.x.x.x:xxxxx. This is the message: This address uses a network port which is normally used for purposes other than Web browsing. Firefox has canceled the request for your protection. How can I allow a specific port? I have searched for the answer and the suggested solution everywhere: "network.security.ports.banned.override" does not exist in about:config, Please don't close this question on account of it being already answered, because even the solution suggested by the kb is out of date and doesn't work. What I need is an answer that works on modern firefox. (why do I use unusual ports? I develop some remote telemetry for embedded systems using REST and a browser is a quick and simple way to verify external connectivity, and no, not every service can use 80 or 443).