IIIMP throws the following exception when closing a parent window of the client component.

Exception occurred during event dispatching:
java.lang.IllegalArgumentException: null source
        at java.lang.Throwable.<init>(Compiled Code)
        at java.lang.Exception.<init>(Compiled Code)
        at java.lang.RuntimeException.<init>(Compiled Code)
        at java.lang.IllegalArgumentException.<init>(Compiled Code)
        at java.util.EventObject.<init>(Compiled Code)
        at java.awt.AWTEvent.<init>(Compiled Code)
        at java.awt.event.InputMethodEvent.<init>(Compiled Code)
        at sun.awt.im.InputMethodContext.dispatchInputMethodEvent(Compiled Code)
        at sun.awt.im.iiimp.IIIMPAdapter.postInputMethodEvent(Compiled Code)
        at sun.awt.im.iiimp.IIIMPAdapter.dispatchCommittedText(Compiled Code)
        at sun.awt.im.iiimp.IIIMPAdapter.access$0(Compiled Code)
        at sun.awt.im.iiimp.IIIMPAdapter$Commit.commitPerformed(Compiled Code)
        at sun.awt.im.iiimp.InputContext.done(Compiled Code)
        at sun.awt.im.iiimp.InputContext.dispose(Compiled Code)
        at sun.awt.im.iiimp.IIIMPAdapter.dispose(Compiled Code)
        at sun.awt.im.InputContext.dispose(Compiled Code)
        at java.awt.Window.dispose(Compiled Code)
        at java.awt.Frame.dispose(Compiled Code)
        at sun.applet.AppletViewer.appletClose(Compiled Code)
        at sun.applet.AppletViewer.processUserAction(Compiled Code)
        at sun.applet.AppletViewer$UserActionListener.actionPerformed(Compiled Code)
        at java.awt.MenuItem.processActionEvent(Compiled Code)
        at java.awt.MenuItem.processEvent(Compiled Code)
        at java.awt.MenuComponent.dispatchEventImpl(Compiled Code)
        at java.awt.MenuComponent.dispatchEvent(Compiled Code)
        at java.awt.EventQueue.dispatchEvent(Compiled Code)
        at java.awt.EventDispatchThread.run(Compiled Code)