Judging by what you wrote, you are using the Java Live Chat link at the top of the page? If so, would guess that the computer you are on does not have Java installed, or a sufficiently high enough version to run it (if that can have an effect that is). Install Java and it should be ok.
Did that not help when I posted in your other thread?
Firefox doesn't know what to do if you click the link, since the IRC protokol is unknown to it. That protocol is used by chat programs like mIRC or Chatzilla. If you have the latter (add-on) added to firefox, it should automatically open a chatzilla connection to the server, otherwise you'll get your browser's error message.
That said, the chat server has been working fine for me in the last few days.
I've been using IE lately (regrettably so) and my IRC Chat on the Combine server is working just fine. Not using mIRC or any other external IRC client either. I have the latest edition of IE right now (IE8, IE 9 Beta is just a waste) as well as every single Java update automatically installed as soon as they show up.
My advice, however extremely simple, is just to make sure you have all Java updates installed. Shockwave, whatever else there is, just go through the works. If that doesn't do it, I'm at a blank. Get a new 'puter I guess. :P
Well, if the owner is a friend, as it sort of sounds like, just let him/her know that Java is a VERY beneficial program. You can download it directly from their site since it's free, so you don't have to worry about those illegal copies just being a trick to get into your computer. If your friend or whatever still denies the request, well than they're just a moron, sorry to say. Although I suppose I could see where they are coming from, but regardless any computer user understands the necessity and importance of Java to view certain web pages.