http://goproblems.com/startsearch.html
The Java applet cannot be loaded by Firefox because the .jar file contains file names starting with "../". Because of the way pathname lookup works, these files cannot be found by the Applet, and the following exception occurs:
Java Plug-in 1.5.0_11
java.lang.NullPointerException
at goban.calcViewable(goban.java:604)
at goban.init(goban.java:210)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
{Posted by rillig}