java.lang.NullPointerException at javax.swing.SwingUtilities.getWindowAncestor(SwingUtilities.java:63) at com.sun.java.swing.plaf.windows.WindowsRootPaneUI$AltProcessor.postProcessKeyEvent(WindowsRootPaneUI.java:158) at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:637) at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:831) at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:741) at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:592) at java.awt.Component.dispatchEventImpl(Component.java:3506) at java.awt.Container.dispatchEventImpl(Container.java:1627) at java.awt.Window.dispatchEventImpl(Window.java:1606) at java.awt.Component.dispatchEvent(Component.java:3477) [catch] at java.awt.EventQueue.dispatchEvent(EventQueue.java:456) at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137) at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)