java.lang.NullPointerException
        at org.netbeans.modules.visualweb.designer.cssengine.CssEngineServiceImpl.getBackgroundImageUrlForElement(CssEngineServiceImpl.java:1069)
        at org.netbeans.modules.visualweb.css.CssBox.initializeBackgroundImage(CssBox.java:485)
        at org.netbeans.modules.visualweb.css.CssBox.initializeBackground(CssBox.java:462)
        at org.netbeans.modules.visualweb.css.ContainerBox.initializeBackground(ContainerBox.java:150)
        at org.netbeans.modules.visualweb.css.PageBox.initializeBackground(PageBox.java:1155)
        at org.netbeans.modules.visualweb.css.CssBox.initializeInvariants(CssBox.java:309)
        at org.netbeans.modules.visualweb.css.CssBox.<init>(CssBox.java:251)
        at org.netbeans.modules.visualweb.css.ContainerBox.<init>(ContainerBox.java:97)
        at org.netbeans.modules.visualweb.css.DocumentBox.<init>(DocumentBox.java:106)
        at org.netbeans.modules.visualweb.css.PageBox.<init>(PageBox.java:112)
        at org.netbeans.modules.visualweb.css.PageBox.<init>(PageBox.java:105)
        at org.netbeans.modules.visualweb.css.PageBox.getPageBox(PageBox.java:139)
        at org.netbeans.modules.visualweb.designer.DesignerPaneUI.resetPageBox(DesignerPaneUI.java:630)
        at org.netbeans.modules.visualweb.designer.WebForm.resetPanePageBox(WebForm.java:2779)
        at org.netbeans.modules.visualweb.designer.jsf.ui.JsfTopComponent.resetDesigner(JsfTopComponent.java:2731)
        at org.netbeans.modules.visualweb.designer.jsf.ui.JsfTopComponent.designerShowing(JsfTopComponent.java:2702)
        at org.netbeans.modules.visualweb.designer.jsf.ui.JsfTopComponent.componentShowing(JsfTopComponent.java:1296)
        at org.netbeans.modules.visualweb.designer.jsf.ui.JsfMultiViewElement.componentShowing(JsfMultiViewElement.java:129)
        at org.netbeans.modules.visualweb.project.jsfloader.OpenEditOverride$MultiViewDelegate.componentShowing(OpenEditOverride.java:178)
        at org.netbeans.core.multiview.MultiViewPeer.showCurrentElement(MultiViewPeer.java:294)
        at org.netbeans.core.multiview.MultiViewPeer.showCurrentElement(MultiViewPeer.java:264)
        at org.netbeans.core.multiview.MultiViewPeer$SelectionListener.selectionChanged(MultiViewPeer.java:689)
        at org.netbeans.core.multiview.MultiViewModel.fireSelectionChanged(MultiViewModel.java:243)
        at org.netbeans.core.multiview.MultiViewModel.setActiveDescription(MultiViewModel.java:115)
        at org.netbeans.core.multiview.MultiViewModel$BtnGroup.setSelected(MultiViewModel.java:293)
        at javax.swing.JToggleButton$ToggleButtonModel.setSelected(JToggleButton.java:237)
        at javax.swing.ButtonGroup.setSelected(ButtonGroup.java:147)
        at org.netbeans.core.multiview.MultiViewModel$BtnGroup.setSelected(MultiViewModel.java:289)
        at org.netbeans.core.multiview.TabsComponent$ButtonMouseListener.mousePressed(TabsComponent.java:456)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:263)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:262)
        at java.awt.Component.processMouseEvent(Component.java:6035)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3260)
        at java.awt.Component.processEvent(Component.java:5803)
        at java.awt.Container.processEvent(Container.java:2058)
        at java.awt.Component.dispatchEventImpl(Component.java:4410)
        at java.awt.Container.dispatchEventImpl(Container.java:2116)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4322)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:3983)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:3916)
        at java.awt.Container.dispatchEventImpl(Container.java:2102)
        at java.awt.Window.dispatchEventImpl(Window.java:2429)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)