Sometimes the next exception occurs:
java.io.FileNotFoundException: Execution was interrupted
        at sun.awt.shell.Win32ShellFolderManager2.createShellFolder(Win32ShellFolderManager2.java:64)
        at sun.awt.shell.ShellFolder.getShellFolder(ShellFolder.java:241)
        at javax.swing.filechooser.FileSystemView.getShellFolder(FileSystemView.java:531)
        at javax.swing.filechooser.FileSystemView.getFiles(FileSystemView.java:455)
        at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run0(BasicDirectoryModel.java:239)
        at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run(BasicDirectoryModel.java:228)
Exception in thread "Basic L&F File Loading Thread" java.lang.NullPointerException
        at javax.swing.filechooser.FileSystemView.getFiles(FileSystemView.java:458)
        at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run0(BasicDirectoryModel.java:239)
        at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run(BasicDirectoryModel.java:228)

It happens when JFileChooser changes current directory while the previous directory hasn't been read yet.