Error: 500 Location: /myCon/servlets/LogOn.htm Internal Servlet Error: java.lang.IllegalStateException: Can't happen - classname is null, who added this ? at org.apache.tomcat.core.ServletWrapper.loadServlet(ServletWrapper.java:261) at org.apache.tomcat.core.ServletWrapper.init(ServletWrapper.java:289) at org.apache.tomcat.core.Handler.service(Handler.java:254) at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372) at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:79 7) at org.apache.tomcat.core.ContextManager.service(ContextManager.java:743) at org.apache.tomcat.service.connector.Ajp12ConnectionHandler.processConnection (Ajp12ConnectionHandler.java:166) at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java, Compiled Code) at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java, Compiled Code) at java.lang.Thread.run(Thread.java:479)