java.lang.NullPointerException: iconBase attribute not specified
   at org.netbeans.core.spi.multiview.MultiViewFactory$MapMVD.get(MultiViewFactory.java:379)
   at org.netbeans.core.spi.multiview.MultiViewFactory$MapMVD.getIcon(MultiViewFactory.java:400)
   at org.netbeans.core.multiview.MultiViewPeer.showCurrentElement(MultiViewPeer.java:359)
   at org.netbeans.core.multiview.MultiViewPeer.showCurrentElement(MultiViewPeer.java:343)
   at org.netbeans.core.multiview.MultiViewPeer$SelectionListener.selectionChanged(MultiViewPeer.java:741)
   at org.netbeans.core.multiview.MultiViewModel.fireSelectionChanged(MultiViewModel.java:246)
   at org.netbeans.core.multiview.MultiViewModel.setActiveDescription(MultiViewModel.java:118)
   at org.netbeans.core.multiview.MultiViewModel$BtnGroup.setSelected(MultiViewModel.java:296)
   at javax.swing.JToggleButton$ToggleButtonModel.setSelected(JToggleButton.java:254)
   at javax.swing.ButtonGroup.setSelected(ButtonGroup.java:164)
   at org.netbeans.core.multiview.MultiViewModel$BtnGroup.setSelected(MultiViewModel.java:292)
   at org.netbeans.core.multiview.TabsComponent$ButtonMouseListener.mousePressed(TabsComponent.java:449)
   at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:280)
   at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:279)
   at java.awt.Component.processMouseEvent(Component.java:6501)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3312)
   at java.awt.Component.processEvent(Component.java:6269)
   at java.awt.Container.processEvent(Container.java:2229)
   at java.awt.Component.dispatchEventImpl(Component.java:4860)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Component.dispatchEvent(Component.java:4686)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4832)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4489)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4422)
   at java.awt.Container.dispatchEventImpl(Container.java:2273)
   at java.awt.Window.dispatchEventImpl(Window.java:2713)
   at java.awt.Component.dispatchEvent(Component.java:4686)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
   at java.awt.EventQueue.access$000(EventQueue.java:101)
   at java.awt.EventQueue$3.run(EventQueue.java:666)
   at java.awt.EventQueue$3.run(EventQueue.java:664)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
   at java.awt.EventQueue$4.run(EventQueue.java:680)
   at java.awt.EventQueue$4.run(EventQueue.java:678)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:162)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)