Injection Exception classes not found

When trying to implement Seam @ViewConfig, this subsytem tries to raise an exception whose class cannot be found.

16:02:06,710 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[/seamproto].[Faces Servlet]] "Servlet.service()" pour la servlet Faces Servlet a généré une exception: java.lang.NoClassDefFoundError: org/jboss/weld/injection/Exceptions
at org.jboss.weld.injection.MethodInjectionPoint.invokeOnInstanceWithSpecialValue(MethodInjectionPoint.java:214) [:6.0.0.Final]
at org.jboss.weld.event.ObserverMethodImpl.sendEvent(ObserverMethodImpl.java:270) [:6.0.0.Final]
at org.jboss.weld.event.ObserverMethodImpl.sendEvent(ObserverMethodImpl.java:253) [:6.0.0.Final]
at org.jboss.weld.event.ObserverMethodImpl.notify(ObserverMethodImpl.java:222) [:6.0.0.Final]
at org.jboss.weld.manager.BeanManagerImpl.notifyObservers(BeanManagerImpl.java:611) [:6.0.0.Final]
at org.jboss.weld.manager.BeanManagerImpl.fireEvent(BeanManagerImpl.java:604) [:6.0.0.Final]
at org.jboss.weld.manager.BeanManagerImpl.fireEvent(BeanManagerImpl.java:598) [:6.0.0.Final]
at org.jboss.seam.faces.event.SeamPreNavigationHandler.handleNavigation(SeamPreNavigationHandler.java:47) [:3.0.1.Final]
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:126) [:2.0.3-]
at javax.faces.component.UICommand.broadcast(UICommand.java:311) [:2.0.3-]
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:781) [:2.0.3-]
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1246) [:2.0.3-]
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:77) [:2.0.3-]
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97) [:2.0.3-]
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:114) [:2.0.3-]
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:308) [:2.0.3-]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:324) [:6.0.0.Final]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:242) [:6.0.0.Final]
at org.jboss.weld.servlet.ConversationPropagationFilter.doFilter(ConversationPropagationFilter.java:67) [:6.0.0.Final]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:274) [:6.0.0.Final]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:242) [:6.0.0.Final]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [:6.0.0.Final]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) [:6.0.0.Final]
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:181) [:6.0.0.Final]
at org.jboss.modcluster.catalina.CatalinaContext$RequestListenerValve.event(CatalinaContext.java:285) [:1.1.0.Final]
at org.jboss.modcluster.catalina.CatalinaContext$RequestListenerValve.invoke(CatalinaContext.java:261) [:1.1.0.Final]
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:88) [:6.0.0.Final]
at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:100) [:6.0.0.Final]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) [:6.0.0.Final]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [:6.0.0.Final]
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158) [:6.0.0.Final]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [:6.0.0.Final]
at org.jboss.web.tomcat.service.request.ActiveRequestResponseCacheValve.invoke(ActiveRequestResponseCacheValve.java:53) [:6.0.0.Final]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:362) [:6.0.0.Final]
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [:6.0.0.Final]
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:654) [:6.0.0.Final]
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:951) [:6.0.0.Final]
at java.lang.Thread.run(Unknown Source) [:1.6.0_16]