Preview image is not shown on content panel

In images folder (beeldbank) select an image. I would expect the image to be shown in the content panel, instead it remains empty. The log contains the stacktrace below:

08.06.2009 15:39:55 ERROR [org.hippoecm.frontend.editor.impl.JcrTemplateStore.getTemplate():170] /hippo:namespaces/hippo/handle
08.06.2009 15:39:55 ERROR [org.hippoecm.frontend.plugin.impl.PluginFactory.createPlugin():89] java.lang.NullPointerException: null
java.lang.reflect.InvocationTargetException
at sun.reflect.GeneratedConstructorAccessor50.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.hippoecm.frontend.plugin.impl.PluginFactory.createPlugin(PluginFactory.java:71)
at org.hippoecm.frontend.plugin.impl.PluginManager.start(PluginManager.java:84)
at org.hippoecm.frontend.plugin.impl.PluginContext.start(PluginContext.java:242)
at org.hippoecm.frontend.plugin.impl.ClusterControl.start(ClusterControl.java:112)
at org.hippoecm.frontend.plugins.cms.edit.AbstractCmsEditor.start(AbstractCmsEditor.java:252)
at org.hippoecm.frontend.plugins.cms.edit.EditorManagerPlugin.createEditor(EditorManagerPlugin.java:123)
at org.hippoecm.frontend.plugins.cms.edit.EditorManagerPlugin.openPreview(EditorManagerPlugin.java:109)
at org.hippoecm.frontend.plugins.cms.edit.BrowserObserver.onEvent(BrowserObserver.java:102)
at org.hippoecm.frontend.model.event.ObservableRegistry$ObservationContext.notifyObservers(ObservableRegistry.java:76)
at org.hippoecm.frontend.model.ModelReference.setModel(ModelReference.java:77)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService$DocumentModelService.updateModel(BrowseService.java:61)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService.browse(BrowseService.java:130)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService$DocumentModelService.setModel(BrowseService.java:69)
at org.hippoecm.frontend.plugins.standards.browse.BrowseService$DocumentModelService.setModel(BrowseService.java:53)
at org.hippoecm.frontend.plugins.standards.list.AbstractListingPlugin.selectionChanged(AbstractListingPlugin.java:149)
at org.hippoecm.frontend.plugins.standards.list.ListCell$1.onEvent(ListCell.java:50)
at org.apache.wicket.ajax.AjaxEventBehavior.respond(AjaxEventBehavior.java:163)
at org.apache.wicket.ajax.AbstractDefaultAjaxBehavior.onRequest(AbstractDefaultAjaxBehavior.java:297)
at org.apache.wicket.request.target.component.listener.BehaviorRequestTarget.processEvents(BehaviorRequestTarget.java:100)
at org.apache.wicket.request.AbstractRequestCycleProcessor.processEvents(AbstractRequestCycleProcessor.java:91)
at org.hippoecm.frontend.PluginRequestCycleProcessor.processEvents(PluginRequestCycleProcessor.java:28)
at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1175)
at org.apache.wicket.RequestCycle.step(RequestCycle.java:1252)
at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1353)
at org.apache.wicket.RequestCycle.request(RequestCycle.java:493)
at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:355)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:200)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.hippoecm.frontend.plugins.login.ConcurrentLoginFilter.doFilter(ConcurrentLoginFilter.java:54)
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:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
at org.hippoecm.frontend.plugin.impl.PluginContext.newCluster(PluginContext.java:74)
at org.hippoecm.frontend.editor.viewer.ViewerPlugin.createTemplate(ViewerPlugin.java:85)
at org.hippoecm.frontend.editor.viewer.ViewerPlugin.onModelChanged(ViewerPlugin.java:68)
at org.apache.wicket.Component.modelChanged(Component.java:2105)
at org.hippoecm.frontend.editor.viewer.ViewerPlugin.<init>(ViewerPlugin.java:57)
... 45 more