Looks like its some issue in 5.1 as application ( xwiki 3.5 ) under same tomcat is running fine. It would be helplful if somebody can throw light on it. ---------- Forwarded message ---------- From: Mohit Gupta &lt;motgupta(a)gmail.com&gt; Date: Tue, Jun 11, 2013 at 12:41 PM Subject: xwiki installation with xwiki-enterprise-web-5.1-milestone-1.war? To: XWiki Users &lt;users(a)xwiki.org&gt; i downloaded the latest version of xwiki i.e xwiki-enterprise-web-5.1-milestone-1.war file and put it in <Tomcat_HomeDirectory>/xwiki ax extracted folder. Now when startup the tomcat i am getting below error Jun 11, 2013 12:32:30 PM org.apache.catalina.core.StandardContext listenerStart SEVERE: Exception sending context initialized event to listener instance of class org.xwiki.container.servlet.XWikiServletContextListener java.lang.NoClassDefFoundError: Failed to get fields for class [org.xwiki.extension.internal.DefaultExtensionLicenseManager] because the class [org/reflections/Configuration] couldn't be found in the ClassLoader. at org.xwiki.component.util.ReflectionUtils.getAllFields(ReflectionUtils.java:71) at org.xwiki.component.annotation.ComponentDescriptorFactory.createComponentDescriptor(ComponentDescriptorFactory.java:132) at org.xwiki.component.annotation.ComponentDescriptorFactory.createComponentDescriptors(ComponentDescriptorFactory.java:105) Am i missing some library?