NullPointerException in jbpm-console when viewing running process

When accessing process instances through jbpm-console, a NullPointerException is thrown:

2008-12-18 10:39:11,928 ERROR [javax.enterprise.resource.webcontainer.jsf.lifecycle] JSF1054: (Phase ID: RENDER_RESPONSE 6, View ID: /sa/procins.xhtml) Exception thrown during phase execution: javax.faces.event.PhaseEvent[source=com.sun.faces.lifecycle.LifecycleImpl@1946a32]
2008-12-18 10:39:11,946 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[/jbpm-console].[Faces Servlet]] Servlet.service() for servlet Faces Servlet threw exception
java.lang.NullPointerException
at java.lang.String.compareTo(String.java:1168)
at java.lang.String.compareTo(String.java:92)
at org.jboss.gravel.data.action.SortActionListener$ELComparator.compare(SortActionListener.java:140)
at java.util.Arrays.mergeSort(Arrays.java:1270)
at java.util.Arrays.sort(Arrays.java:1210)
at java.util.Collections.sort(Collections.java:159)
at org.jboss.gravel.data.action.SortActionListener.processAction(SortActionListener.java:83)
at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88)
at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:771)
at javax.faces.component.UICommand.broadcast(UICommand.java:372)
at org.jboss.gravel.action.handler.ResponseActionsHandler.onComponentPopulated(ResponseActionsHandler.java:24)
at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:180)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.tag.jsf.ComponentHandler.applyNextHandler(ComponentHandler.java:314)
at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:169)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.tag.jsf.ComponentHandler.applyNextHandler(ComponentHandler.java:314)
at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:169)
at org.jboss.gravel.common.handler.CollectionHandler.applyNextHandler(CollectionHandler.java:155)
at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:169)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.tag.jsf.ComponentHandler.applyNextHandler(ComponentHandler.java:314)
at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:169)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.tag.jsf.ComponentHandler.applyNextHandler(ComponentHandler.java:314)
at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:169)
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:143)
at com.sun.facelets.tag.ui.DecorateHandler.apply(DecorateHandler.java:105)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.tag.jsf.ComponentHandler.applyNextHandler(ComponentHandler.java:314)
at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:169)
at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
at com.sun.facelets.tag.jsf.ComponentHandler.applyNextHandler(ComponentHandler.java:314)
at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:169)
at com.sun.facelets.tag.ui.DefineHandler.apply(DefineHandler.java:58)
at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:128)
at com.sun.facelets.impl.DefaultFaceletContext$TemplateManager.apply(DefaultFaceletContext.java:306)
at com.sun.facelets.impl.DefaultFaceletContext.includeDefinition(DefaultFaceletContext.java:279)
at com.sun.facelets.tag.ui.InsertHandler.apply(InsertHandler.java:68)
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:143)
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.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:143)
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:503)
at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:546)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:189)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:109)
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.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:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:524)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
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:157)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)
at java.lang.Thread.run(Thread.java:619)

Procedure to reproduce with attached process definition:

• login to jbpm-console
• click [Examine] of the process definition
• click [Start] in the left pane
• click [Tokens] in the left pane
• click [Signal] of the token