What means Assertion Failed?!?!

Question

Hi guys!!! Here are some duke dollars from a expert.....
I use "Tomcat-5.5.4", "jwsdp-1.5", "jdk1.5.0" and "jsf-1.1_01". PLEASE I NEED HELP!!!!!!
The sample application that come together jsf zipped file works properly when I put its on my webapp folder!!!!!
But my application don't work and I always get the error "Assertion Failed". The entire exception message is post below. Please I lost a week on this problem and I don't know what to do to solve this!!!!
javax.faces.el.EvaluationException: javax.faces.FacesException: Assertion Failed
     at com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:206)
     at com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:154)
     at javax.faces.component.UIOutput.getValue(UIOutput.java:147)
     at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:82)
     at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:191)
     at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:169)
     at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:720)
     at javax.faces.webapp.UIComponentTag.encodeEnd(UIComponentTag.java:623)
     at javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:546)
     at com.sun.faces.taglib.html_basic.OutputTextTag.doEndTag(OutputTextTag.java:173)
     at org.apache.jsp.index_jsp._jspx_meth_h_outputText_0(org.apache.jsp.index_jsp:182)
     at org.apache.jsp.index_jsp._jspx_meth_h_form_0(org.apache.jsp.index_jsp:141)
     at org.apache.jsp.index_jsp._jspx_meth_f_view_0(org.apache.jsp.index_jsp:106)
     at org.apache.jsp.index_jsp._jspService(org.apache.jsp.index_jsp:72)
     at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:99)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
     at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:325)
     at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
     at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:245)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
     at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:674)
     at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:465)
     at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:400)
     at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:303)
     at com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:322)
     at com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:130)
     at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:87)
     at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:200)
     at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:117)
     at javax.faces.webapp.FacesServlet.service(FacesServlet.java:198)
     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
     at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
     at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:825)
     at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:731)
     at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:526)
     at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
     at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
     at java.lang.Thread.run(Thread.java:595)
Thanks all.
Giscard

Answer 1

According to your exception log, the exception is thrown by ValueBindingImpl.getValue().
Why don't you set a breakpoint on it and debug stepwise?
The code of getValue() is as follows:
protected Object getValue(FacesContext context, String toEvaluate)
        throws EvaluationException, PropertyNotFoundException {
        Object result = null;
     ExpressionInfo info = checkoutExpressionInfo();
        try {
            info.setExpressionString(toEvaluate);
            info.setExpectedType(Object.class);
            info.setFacesContext(context);
            info.setVariableResolver(application.getVariableResolver());
            info.setPropertyResolver(application.getPropertyResolver());
//** I guess here is the ground zero! **/
            result = Util.getExpressionEvaluator().evaluate(info);
            if (log.isDebugEnabled()) {
                log.debug("getValue Result:" + result);
        } catch (Throwable e) {
            if (e instanceof ElException) {
                if (log.isDebugEnabled()) {
                    Throwable l = e;
                    Throwable t = ((ElException) e).getCause();
                    if (t != null) {
                        l = t;
                    log.debug("getValue Evaluation threw exception:", l);
          checkinExpressionInfo(info);
                throw new EvaluationException(e);
            } else if (e instanceof PropertyNotFoundException) {
                if (log.isDebugEnabled()) {
                    Throwable l = e;
                    Throwable t = ((PropertyNotFoundException) e).getCause();
                    if (t != null) {
                        l = t;
                    log.debug("getValue Evaluation threw exception:", l);
                // Just rethrow it to keep detailed message
          checkinExpressionInfo(info);
                throw (PropertyNotFoundException) e;
            } else {
                if (log.isDebugEnabled()) {
                    log.debug("getValue Evaluation threw exception:", e);
          checkinExpressionInfo(info);
                throw new EvaluationException(e);
     checkinExpressionInfo(info);
        return result;
    }