See linked issue for setup.

After setting up lots of operation history entries, go to the Operations subsystem page.  Find an entry for a "testConnection" op on DefaultDS.  Click the DefaultDS link to go to the resource page.

Get stack trace:

javax.faces.FacesException: javax.el.ELException: /rhq/resource/navigation/ResourcesTree.xhtml @49,92 roots="#{ResourceTreeModelUIBean.roots}": Error reading 'roots' on type org.rhq.enterprise.gui.navigation.resource.ResourceTreeModelUIBean
	at org.richfaces.component.html.HtmlRecursiveTreeNodesAdaptor.getRoots(HtmlRecursiveTreeNodesAdaptor.java:183)
	at org.richfaces.component.UIRecursiveTreeNodesAdaptor.getData(UIRecursiveTreeNodesAdaptor.java:55)
	at org.richfaces.component.UITreeNodesAdaptor$1.getData(UITreeNodesAdaptor.java:54)
	at org.richfaces.model.StackingTreeModel.getDataModel(StackingTreeModel.java:83)
	at org.richfaces.model.StackingTreeModel.doWalk(StackingTreeModel.java:309)
	at org.richfaces.model.StackingTreeModel.walk(StackingTreeModel.java:381)
	at org.richfaces.component.UITree.walk(UITree.java:422)
	at org.richfaces.renderkit.TreeRendererBase.writeContent(TreeRendererBase.java:655)
	at org.richfaces.renderkit.TreeRendererBase.encodeChildren(TreeRendererBase.java:601)
	at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
	at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:234)
	at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:239)
	at com.sun.faces.renderkit.html_basic.GroupRenderer.encodeChildren(GroupRenderer.java:106)
	at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:930)
	at javax.faces.render.Renderer.encodeChildren(Renderer.java:148)
	at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:930)
	at javax.faces.component.UIComponent.encodeAll(UIComponent.java:933)
	at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:592)
	at org.rhq.enterprise.gui.common.framework.FaceletRedirectionViewHandler.renderView(FaceletRedirectionViewHandler.java:64)
	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.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:532)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.rhq.enterprise.gui.legacy.WebUserTrackingFilter.doFilter(WebUserTrackingFilter.java:47)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.rhq.enterprise.gui.legacy.AuthenticationFilter.doFilter(AuthenticationFilter.java:129)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.rhq.enterprise.gui.common.upload.MultipartFilter.doFilter(MultipartFilter.java:63)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	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.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.rhq.helpers.rtfilter.filter.RtFilter.doFilter(RtFilter.java:124)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	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.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)
Caused by: javax.el.ELException: /rhq/resource/navigation/ResourcesTree.xhtml @49,92 roots="#{ResourceTreeModelUIBean.roots}": Error reading 'roots' on type org.rhq.enterprise.gui.navigation.resource.ResourceTreeModelUIBean
	at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:76)
	at org.richfaces.component.html.HtmlRecursiveTreeNodesAdaptor.getRoots(HtmlRecursiveTreeNodesAdaptor.java:181)
	... 79 more
Caused by: java.lang.NullPointerException
	at org.rhq.enterprise.gui.navigation.resource.ResourceTreeModelUIBean.loadTree(ResourceTreeModelUIBean.java:83)
	at org.rhq.enterprise.gui.navigation.resource.ResourceTreeModelUIBean.getTreeNode(ResourceTreeModelUIBean.java:294)
	at org.rhq.enterprise.gui.navigation.resource.ResourceTreeModelUIBean.getRoots(ResourceTreeModelUIBean.java:303)
	at sun.reflect.GeneratedMethodAccessor904.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at javax.el.BeanELResolver.getValue(BeanELResolver.java:62)
	at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:53)
	at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
	at org.jboss.el.parser.AstPropertySuffix.getValue(AstPropertySuffix.java:53)
	at org.jboss.el.parser.AstValue.getValue(AstValue.java:67)
	at org.jboss.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
	at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:71)
	... 80 more