I've just upgraded from JBoss 4.0.5 to 4.2.0 and am having all sorts of trouble deploying my web app. I was using Selenium to test the web pages, but have removed that because I suspected that there was a compatibility problem, but the problem still exists (actually it was complaing about org.apache.commons.digester) This doesn't make any sense to me because I can't even see any trace of where I'm calling JSF methods... 02:58:02,703 INFO [TomcatDeployer] deploy, ctxPath=/mojoWeb, warUrl=.../deploy/mojoWeb.war/ | 02:58:07,640 INFO [STDOUT] 02:58:07,640 ERROR [[/mojoWeb]] Exception sending context initialized event to listener instance of class com.sun.faces.config.ConfigureListener | java.lang.IncompatibleClassChangeError: Class org.jnp.server.NamingServer does not implement the requested interface org.jnp.interfaces.Naming | at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:625) | at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:716) | at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:587) | at javax.naming.InitialContext.lookup(InitialContext.java:392) | at com.sun.faces.config.WebConfiguration.processJndiEntries(WebConfiguration.java:441) | at com.sun.faces.config.WebConfiguration.<init>(WebConfiguration.java:86) | at com.sun.faces.config.WebConfiguration.getInstance(WebConfiguration.java:139) | at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:249) | at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3854) | at org.apache.catalina.core.StandardContext.start(StandardContext.java:4359) | at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:761) | at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:741) | at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:553) | at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) | at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) | at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) | at java.lang.reflect.Method.invoke(Method.java:597) | at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:297) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4046577#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...