Java Probelm?

[Jack]

When I save a variable, there appears a lot of strange reminders as
follows. I do not know why

Actually, my command is

save MOFEPSAMPLE sample -ASCII -TABS
------------------------------------------------------

java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(Unknown Source)
at javax.swing.ImageIcon.<init>(Unknown Source)
at
com.sun.java.swing.plaf.windows.WindowsFileChooserUI$ShortCutPanel.&lt
;init>(Unknown Source)
at
com.sun.java.swing.plaf.windows.WindowsFileChooserUI.installComponents
(Unknown Source)
at javax.swing.plaf.basic.BasicFileChooserUI.installUI(Unknown
Source)
at
com.sun.java.swing.plaf.windows.WindowsFileChooserUI.installUI(Unknown
Source)
at javax.swing.JComponent.setUI(Unknown Source)
at javax.swing.JFileChooser.updateUI(Unknown Source)
at javax.swing.JFileChooser.setup(Unknown Source)
at javax.swing.JFileChooser.<init>(Unknown Source)
at javax.swing.JFileChooser.<init>(Unknown Source)
at
com.mathworks.mwswing.MJFileChooser.<init>(MJFileChooser.java:12
1)
at
com.mathworks.mde.editor.EditorDocument.saveFileAs(EditorDocument.java
:528)
at
com.mathworks.mde.editor.EditorDocument$4.update(EditorDocument.java:1
89)
at java.util.Observable.notifyObservers(Unknown Source)
at
com.mathworks.mde.editor.GenericAction$RegisteredObservable.notifyRegi
steredObservers(GenericAction.java:327)
at
com.mathworks.mde.editor.GenericAction.actionPerformed(GenericAction.j
ava:318)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at
javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(Unknown
Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown
Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.AbstractButton.doClick(Unknown Source)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
at
javax.swing.plaf.basic.BasicMenuItemUI$MouseInputHandler.mouseReleased
(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown
Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown
Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
>>