java.lang.NullPointerException
   at sun.awt.shell.Win32ShellFolder2.pidlsEqual(Win32ShellFolder2.java:498)
   at sun.awt.shell.Win32ShellFolder2.equals(Win32ShellFolder2.java:491)
   at sun.awt.shell.Win32ShellFolderManager2.isFileSystemRoot(Win32ShellFolderManager2.java:350)
   at sun.awt.shell.ShellFolder.isFileSystemRoot(ShellFolder.java:242)
   at javax.swing.filechooser.FileSystemView.isFileSystemRoot(FileSystemView.java:323)
   at javax.swing.filechooser.WindowsFileSystemView.isTraversable(WindowsFileSystemView.java:657)
   at javax.swing.JFileChooser.isTraversable(JFileChooser.java:1561)
   at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run0(BasicDirectoryModel.java:232)
   at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run(BasicDirectoryModel.java:211)