Substance Java - Exception étrange

Question

J'utilise la version 6.0 de l'aspect substantiel et me sens dans mon application Java Swing. L'application fonctionne très bien pour moi, mais certains des utilisateurs de l'application, en particulier ceux qui utilisent Windows 7, obtiennent une exception de substance:

java.lang.InternalError: Unable to instantiate org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.colorchooser.ColorPalettesChooser
at org.pushingpixels.substance.internal.ui.SubstanceColorChooserUI.createDefaultChoosers(SubstanceColorChooserUI.java)
at org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.Quaqua13ColorChooserUI.__org__pushingpixels__substance__internal__contrib__randelshofer__quaqua__Quaqua13ColorChooserUI__installUI(Quaqua13ColorChooserUI.java)
at org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.Quaqua13ColorChooserUI.installUI(Quaqua13ColorChooserUI.java)
at org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.Quaqua14ColorChooserUI.__org__pushingpixels__substance__internal__contrib__randelshofer__quaqua__Quaqua14ColorChooserUI__installUI(Quaqua14ColorChooserUI.java)
at org.pushingpixels.substance.internal.contrib.randelshofer.quaqua.Quaqua14ColorChooserUI.installUI(Quaqua14ColorChooserUI.java)
at org.pushingpixels.substance.internal.ui.SubstanceColorChooserUI.__org__pushingpixels__substance__internal__ui__SubstanceColorChooserUI__installUI(SubstanceColorChooserUI.java)
at org.pushingpixels.substance.internal.ui.SubstanceColorChooserUI.installUI(SubstanceColorChooserUI.java)
at javax.swing.JComponent.setUI(Unknown Source)
at javax.swing.JColorChooser.setUI(Unknown Source)
at javax.swing.JColorChooser.updateUI(Unknown Source)
at javax.swing.JColorChooser.(Unknown Source)
at javax.swing.JColorChooser.(Unknown Source)
at javax.swing.JColorChooser.(Unknown Source)
at org.jdesktop.swingx.JXColorSelectionButton.getChooser(JXColorSelectionButton.java)
at org.jdesktop.swingx.JXColorSelectionButton$1.propertyChange(JXColorSelectionButton.java)
at java.beans.PropertyChangeSupport.fire(Unknown Source)
at java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
at java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
at java.awt.Component.firePropertyChange(Unknown Source)
at java.awt.Component.setBackground(Unknown Source)
at javax.swing.JComponent.setBackground(Unknown Source)

Cette exception se produit dans la dernière ligne de ce code:

JXColorSelectionButton myColorSelectionButton = new JXColorSelectionButton();

myColorSelectionButton.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
myColorSelectionButton.setFocusPainted(false);
contentPane.add(myColorSelectionButton, cc.xy(29, 19));
/**
  * Some code here
  */
myColorSelectionButton.setBackground( Color.WHITE );  // Excepton occurres here !!

Je ne trouve pas un endroit pour poser cette question de substance, donc si vous pouvez m'aider, ce serait apprécié.