As a web developer I often use non-standard ports for web sites which I’m testing. Firefox has recently started blocking some of these ports so this post shows how to get around this.
Type about:config in the URL area and hit enter.
Type network.security.ports.banned.override in the filter area. Nothing will show up if you haven’t done this before.
Right click in the empty preferences area and select New->String
Enter network.security.ports.banned.override as the string name.
Enter a comma separated list of port numbers as the value. I haven’t tested it but supposedly you can also enter port ranges with a dash.
This should have unblocked those ports and the error should go away…
