java.lang.NullPointerException
        at sun.font.FontDesignMetrics$MetricsKey.init(FontDesignMetrics.java:199)
        at sun.font.FontDesignMetrics.getMetrics(FontDesignMetrics.java:267)
        at sun.swing.SwingUtilities2.getFontMetrics(SwingUtilities2.java:954)
        at javax.swing.JComponent.getFontMetrics(JComponent.java:1597)
        at javax.swing.plaf.synth.SynthTabbedPaneUI.getFontMetrics(SynthTabbedPaneUI.java:733)
        at javax.swing.plaf.synth.SynthTabbedPaneUI.getFontMetrics(SynthTabbedPaneUI.java:729)
        at javax.swing.plaf.basic.BasicTabbedPaneUI$TabbedPaneLayout.calculateTabRects(BasicTabbedPaneUI.java:2525)
        at javax.swing.plaf.basic.BasicTabbedPaneUI$TabbedPaneLayout.calculateLayoutInfo(BasicTabbedPaneUI.java:2488)
        at javax.swing.plaf.synth.SynthTabbedPaneUI$2.calculateLayoutInfo(SynthTabbedPaneUI.java:781)
        at javax.swing.plaf.basic.BasicTabbedPaneUI$TabbedPaneLayout.layoutContainer(BasicTabbedPaneUI.java:2383)
        at java.awt.Container.layout(Container.java:1432)
        at java.awt.Container.doLayout(Container.java:1421)
        at java.awt.Container.validateTree(Container.java:1519)
        at java.awt.Container.validate(Container.java:1491)
        at javax.swing.plaf.basic.BasicTabbedPaneUI.ensureCurrentLayout(BasicTabbedPaneUI.java:1421)
        at javax.swing.plaf.basic.BasicTabbedPaneUI.getTabBounds(BasicTabbedPaneUI.java:1441)
        at javax.swing.plaf.basic.BasicTabbedPaneUI.repaintTab(BasicTabbedPaneUI.java:1970)
        at javax.swing.plaf.basic.BasicTabbedPaneUI.access$2200(BasicTabbedPaneUI.java:37)
        at javax.swing.plaf.basic.BasicTabbedPaneUI$Handler.focusLost(BasicTabbedPaneUI.java:3633)
        at java.awt.Component.processFocusEvent(Component.java:5991)
        at java.awt.Component.processEvent(Component.java:5855)
        at java.awt.Container.processEvent(Container.java:2058)
        at java.awt.Component.dispatchEventImpl(Component.java:4466)
        at java.awt.Container.dispatchEventImpl(Container.java:2116)
        at java.awt.Component.dispatchEvent(Component.java:4296)
        at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1848)
        at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:889)
        at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:562)
        at java.awt.Component.dispatchEventImpl(Component.java:4338)
        at java.awt.Container.dispatchEventImpl(Container.java:2116)
        at java.awt.Component.dispatchEvent(Component.java:4296)
        at java.awt.KeyboardFocusManager.dispatchAndCatchException(KeyboardFocusManager.java:2555)
        at java.awt.KeyboardFocusManager.processCurrentLightweightRequests(KeyboardFocusManager.java:2641)
        at java.awt.KeyboardFocusManager$1.run(KeyboardFocusManager.java:2756)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        at org.netbeans.core.TimeableEventQueue.dispatchEvent(TimeableEventQueue.java:104)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:284)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)