java.lang.NullPointerException
        at javax.swing.JTable.prepareRenderer(JTable.java:5669)
        at javax.swing.plaf.synth.SynthTableUI.paintCell(SynthTableUI.java:605)
        at javax.swing.plaf.synth.SynthTableUI.paintCells(SynthTableUI.java:502)
        at javax.swing.plaf.synth.SynthTableUI.paint(SynthTableUI.java:291)
        at javax.swing.plaf.synth.SynthTableUI.update(SynthTableUI.java:217)
        at javax.swing.JComponent.paintComponent(JComponent.java:763)
        at javax.swing.JComponent.paint(JComponent.java:1027)
        at javax.swing.JComponent.paintToOffscreen(JComponent.java:5122)
        at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:285)
        at javax.swing.RepaintManager.paint(RepaintManager.java:1128)
        at javax.swing.JComponent._paintImmediately(JComponent.java:5070)
        at javax.swing.JComponent.paintImmediately(JComponent.java:4880)
        at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:723)
        at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:679)
        at javax.swing.RepaintManager.seqPaintDirtyRegions(RepaintManager.java:659)
        at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(SystemEventQueueUtilities.java:128)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        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.pumpEventsForFilter(EventDispatchThread.java:177)
        at java.awt.Dialog$1.run(Dialog.java:1039)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        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)