HTTP Status 500 -
 
type Exception report
message 
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException
	org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:395)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:322)
	com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:130)
	com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:87)
	com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:200)
	com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:117)
	javax.faces.webapp.FacesServlet.service(FacesServlet.java:198)
	org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:100)
	org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:147)
root cause
java.lang.NullPointerException
	com.sun.faces.renderkit.html_basic.CommandLinkRenderer.getHiddenFieldName(CommandLinkRenderer.java:136)
	com.sun.faces.renderkit.html_basic.CommandLinkRenderer.encodeEnd(CommandLinkRenderer.java:318)
	javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:720)
	javax.faces.webapp.UIComponentTag.encodeEnd(UIComponentTag.java:623)
	javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:546)
	com.sun.faces.taglib.html_basic.CommandLinkTag.doEndTag(CommandLinkTag.java:505)
	org.apache.jsp.protected_.currentassistance.edit_jsp._jspx_meth_h_commandLink_0(edit_jsp.java:4983)
	org.apache.jsp.protected_.currentassistance.edit_jsp._jspService(edit_jsp.java:1014)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:322)
	com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:130)
	com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:87)
	com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:200)
	com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:117)
	javax.faces.webapp.FacesServlet.service(FacesServlet.java:198)
	org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:100)
	org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:147)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.20 logs.