Index: src/main/java/common/javax/swing/JInternalFrame.java =================================================================== --- src/main/java/common/javax/swing/JInternalFrame.java (revision 489013) +++ src/main/java/common/javax/swing/JInternalFrame.java (working copy) @@ -170,9 +170,13 @@ // so, we cannot write here just // return getInternalFrame().getDesktopPane(); Container result = SwingUtilities.getAncestorOfClass(JDesktopPane.class, this); + if (result == null) { - return getInternalFrame().getDesktopPane(); + if(getInternalFrame() != null) { + result = getInternalFrame().getDesktopPane(); + } } + return (JDesktopPane) result; }