I Cant get this to work!!

I am trying to play Thud but when I started it up at first I got to the console screen but then encountered errors such as have been described before in other topics and I now can not get past my Java loading screen to it and when I opened the Java console when it failed it said

java.lang.IllegalThreadStateException
at java.lang.Thread.start(Unknown Source)
at ThudChat.start(Unknown Source)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

which was repeated.
Any suggestions?