java.lang.IllegalArgumentException: cannot add to layout: constraint must be a GridBagConstraint
java.lang.IllegalArgumentException: cannot add to layout: constraint must be a GridBagConstraint
        at java.awt.GridBagLayout.addLayoutComponent(GridBagLayout.java:533)
        at java.awt.Container.addImpl(Container.java:380)
        at java.awt.Container.add(Container.java:238)
        at javax.swing.plaf.basic.BasicToolBarUI.setFloating(BasicToolBarUI.java:447)
        at javax.swing.plaf.basic.BasicToolBarUI$FrameListener.windowClosing(BasicToolBarUI.java:702)
        at java.awt.Window.processWindowEvent(Window.java:798)
        at javax.swing.JFrame.processWindowEvent(JFrame.java:241)
        at java.awt.Window.processEvent(Window.java:774)
        at java.awt.Component.dispatchEventImpl(Component.java:2593)
        at java.awt.Container.dispatchEventImpl(Container.java:1214)
        at java.awt.Window.dispatchEventImpl(Window.java:912)
        at java.awt.Component.dispatchEvent(Component.java:2497)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:333)
[catch] at java.awt.EventDispatchThread.pumpOneEvent(EventDispatchThread.java:103)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:84)