This is almost always means Netscape can't find one of the classes it needs to run the applet. Check to make sure that the classes your program uses are in the CODEBASE, the CLASSPATH, or somewhere else Netscape can find them. It's not uncommon to get this error when you first test a new package or class you've written with Netscape. If you've only tested it with the applet viewer or an IDE, then the applet viewer or the IDE may have included the current directory in the CLASSPATH where Netscape does not. Therefore the applet viewer can find the right class, but Netscape can't. Explicitly add the path containing your class or package to the CLASSPATH as specified in the previous question.
Posted in: Java