Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: com/toedter/calendar/
JDateChooser
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
    at java.lang.Class.getMethod0(Class.java:3018)
    at java.lang.Class.getMethod(Class.java:1784)
    at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544
)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)

Caused by: java.lang.ClassNotFoundException: com.toedter.calendar.JDateChooser
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 7 more

import com.toedter.calendar.JDateChooser;
public class Login implements ActionListener {
    private JFrame ourFrame = new JFrame("Login");

    JTextField user_text = new JTextField();
    JPasswordField pass_text = new JPasswordField();
    static JDateChooser calendario = new JDateChooser();

    JButton yesButton = new JButton("Confirmar");
    JButton noButton = new JButton("Cancelar");

    public Login() {
        ourFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        ourFrame.setBounds(600, 300, 400, 250);

        Container container = ourFrame.getContentPane();
        container.setLayout(null);

        JLabel logo1 = new JLabel("LOGIN CLEARQUEST");
        logo1.setBounds(130, 10, 250, 20);

        JLabel user_label = new JLabel("Usuário:");
        user_label.setBounds(20, 35, 250, 30);

        JLabel pass_label = new JLabel("Senha:");
        pass_label.setBounds(20, 70, 250, 30);

        user_text.setBounds(70, 40, 250, 20);
        pass_text.setBounds(70, 75, 250, 20);

        JLabel logo2 = new JLabel("INSIRA A DATA DO ÚLTIMO RELATÓRIO");
        logo2.setBounds(83, 100, 250, 30);
        calendario.setBounds(83, 130, 210, 25);

        yesButton.setBounds(70, 170, 100, 30);
        yesButton.addActionListener(this);

        noButton.setBounds(210, 170, 100, 30);
        noButton.addActionListener(this);

        container.add(logo1);
        container.add(user_label);
        container.add(pass_label);
        container.add(user_text);
        container.add(pass_text);
        container.add(logo2);
        container.add(calendario);
        container.add(yesButton);
        container.add(noButton);
        ourFrame.setVisible(true);
    }

    @SuppressWarnings("deprecation")
    public void actionPerformed(ActionEvent aE) {
        if (aE.getSource() == yesButton) {
            String user = user_text.getText();
            String pass = pass_text.getText();

            RESTInvoker rest = new RESTInvoker(user, pass);
            String json = rest.getDataFromServer();

            try {
                // TODO pega os dados do json (arquivo txt retirado do clearquest) e joga em um Array de testes
                Teste[] teste = null;
                teste = Json.criarJson(teste, json);

                DateFormat dateFormat = new SimpleDateFormat("yyyyMMdd");
                Date date = new Date();

                String caminhoTemplate = Variaveis.getCaminhoTemplate();
                String caminhoDestino = Variaveis.getCaminhoExcel() + dateFormat.format(date) + ".xls";

                // verificar o caminho
                CriacaoExcel.criandoArquivo(caminhoTemplate, caminhoDestino, teste);

            }

            catch (InvalidFormatException e) {
                CaixaDialogo.exibirErro(e.getMessage());
            }

            catch (ParseException e) {
                CaixaDialogo.exibirErro(e.getMessage());
            }

        } else if (aE.getSource() == noButton) {
            System.exit(0);
        }

    }

    // envia a data, do relaatório antigo, escolhida pelo usuario
    public static Date enviaData() {
        return calendario.getDate();
    }

    public static void main(String[] args) {
        // para setar o foco nos botões
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                UIManager.put("Button.defaultButtonFollowsFocus", Boolean.TRUE);
                new Login();
            }
        });
    }
}