I'm trying to reproduce a problem I'm experiencing with Ajax4JSF and Seam so I've started by trying to convert the Booking example to the JSF RI 1.2.03. web.xml -- I switched from: <listener-class>org.apache.myfaces.webapp.StartupServletContextListener</listener-class> to: <listener-class>com.sun.faces.config.ConfigureListener</listener-class> Then i switched out the myfaces-imp and api jars for Sun's versions. Then I deployed on a jboss 4.0.5 configuration that has the jsf jars instead of the myfaces jars (neither of which are deployed with the example). While everything works as expected with myfaces, doing the above switch to the RI gives the following exception. Any ideas what's wrong? com.sun.facelets.FaceletException: Could not instantiate feature[compiler.ExpressionFactory]: org.jboss.seam.ui.facelet.SeamExpressionFactory at com.sun.facelets.compiler.Compiler.featureInstance(Compiler.java:153) at com.sun.facelets.compiler.Compiler.createExpressionFactory(Compiler.java:127) at com.sun.facelets.impl.DefaultFaceletFactory.createFacelet(DefaultFaceletFactory.java:193) at com.sun.facelets.impl.DefaultFaceletFactory.getFacelet(DefaultFaceletFactory.java:141) at com.sun.facelets.impl.DefaultFaceletFactory.getFacelet(DefaultFaceletFactory.java:93) at com.sun.facelets.FaceletViewHandler.buildView(FaceletViewHandler.java:503) at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:553) at org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:101) at org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:197) at org.jboss.seam.jsf.SeamViewHandler.renderView(SeamViewHandler.java:59) at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:134) at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:248) at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:144) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:245) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.jboss.seam.servlet.SeamExceptionFilter.doFilter(SeamExceptionFilter.java:45) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.jboss.seam.servlet.SeamRedirectFilter.doFilter(SeamRedirectFilter.java:32) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:67) at org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:223) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105) at org.jboss.web.tomcat.tc5.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:156) 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:869) at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664) at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527) at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112) at java.lang.Thread.run(Thread.java:595) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3985566#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...