Goto "Manage Hudson" page http://127.0.0.1:7080/hudson/manage and
click on "Reload Configuration from Disk" link.

We can see a HTTP Status 500 - page with below Exception

type Exception report

message

description The server encountered an internal error () that prevented it from
fulfilling this request.

exception

javax.servlet.ServletException: org.apache.commons.jelly.JellyTagException:
jar:file:/E:/jboss-4.2.2.GA/jboss-
4.2.2.GA/server/default/tmp/deploy/tmp18793hudson-exp.war/WEB-INF/lib/hudson-
core-1.228.jar!/lib/layout/layout.jelly:16:101: <j:jelly>
java.lang.AssertionError
org.kohsuke.stapler.jelly.JellyClassTearOff.serveIndexJelly
(JellyClassTearOff.java:98)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:416)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:361)
org.kohsuke.stapler.Stapler.service(Stapler.java:121)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:38)
hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:30)
hudson.security.HudsonFilter.doFilter(HudsonFilter.java:88)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter
(ReplyHeaderFilter.java:96)

root cause

org.apache.commons.jelly.JellyTagException: jar:file:/E:/jboss-4.2.2.GA/jboss-
4.2.2.GA/server/default/tmp/deploy/tmp18793hudson-exp.war/WEB-INF/lib/hudson-
core-1.228.jar!/lib/layout/layout.jelly:16:101: <j:jelly>
java.lang.AssertionError
org.apache.commons.jelly.impl.TagScript.handleException
(TagScript.java:713)
org.apache.commons.jelly.impl.TagScript.run(TagScript.java:282)
org.apache.commons.jelly.impl.DynamicTag.doTag(DynamicTag.java:80)
org.apache.commons.jelly.impl.TagScript.run(TagScript.java:262)
org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
org.apache.commons.jelly.TagSupport.invokeBody(TagSupport.java:186)
org.apache.commons.jelly.tags.core.JellyTag.doTag(JellyTag.java:45)

App Server is jboss-4.2.2.GA.