The problem appears when you build the richfaces-demo application from WFK source distribution and try to replace richfaces libs for libs from binary dist. Files ui.pack.js and skin.xcss are not present in richfaces-ui lib. The following error appears in the log.

21:33:12,415 SEVERE [application] jsf.cannot_instantiate_component_error
21:33:12,487 ERROR [viewhandler] Error Rendering View[/welcome.xhtml]
javax.faces.FacesException: Expression Error: Named Object: org.ajax4jsf.Repeat not found.
at com.sun.faces.application.ApplicationImpl.createComponent(ApplicationImpl.java:570)
at org.jboss.seam.jsf.SeamApplication.createComponent(SeamApplication.java:92)
at org.richfaces.ui.application.StateApplication.createComponent(StateApplication.java:132)
at com.sun.facelets.tag.jsf.ComponentHandler.createComponent(ComponentHandler.java:243)
at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:139)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:119)
at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:248)
at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:294)
at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:273)
at com.sun.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:140)
at com.sun.facelets.tag.ui.IncludeHandler.apply(IncludeHandler.java:65)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:119)
at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:248)
at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:294)
at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:273)
at com.sun.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:140)
at com.sun.facelets.tag.ui.IncludeHandler.apply(IncludeHandler.java:65)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:248)
at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:294)
at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:273)
at com.sun.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:140)
at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:113)
at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
at com.sun.facelets.impl.DefaultFacelet.apply(DefaultFacelet.java:95)
at com.sun.facelets.FaceletViewHandler.buildView(FaceletViewHandler.java:524)
at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:567)
at org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:100)
at org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:176)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:110)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:266)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:38)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:390)
at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:517)
at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.debug.hot.HotDeployFilter.doFilter(HotDeployFilter.java:51)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:638)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:444)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:382)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:310)
at org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:696)
at org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:667)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:59)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:369)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:322)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:249)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:235)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:190)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92)
at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:829)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:601)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)