Java- RuntimeException- Uncompilable source code - Erroneous tree type

Question

I'm new in Java also I'm new in this website, so I'm sorry if the error is obvious, but I got an error, that I dont know what it means, I have try everything to fix it.

I'm currently writing a basic aplication library, with some swing interface, but the problem is when trying to create a window of the form of books, there is the relevant code.

This is the principal window.

 public class VentanaPrincipal extends javax.swing.JFrame {

   public VentanaPrincipal() {
     initComponents();
     this.setLocationRelativeTo(null);
}

private void bt_salirActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:
    EscribirBinario escritor = new EscribirBinario();
    //   Collections.sort(ListaClientes.clientes);

    if (escritor.abrir(Main.archivo1)) {
        for (int indice = 0; indice < ListaClientes.clientes.size(); indice++) {
            escritor.escribir(ListaClientes.clientes.get(indice));
        }
        escritor.cerrar();
    }
    System.exit(0);
}                                        

private void bt_clienteActionPerformed(java.awt.event.ActionEvent evt) {                                           

    MantenimientoCliente clientes = new MantenimientoCliente(this, true);
    clientes.setVisible(true);
}                                          

private void bt_libroActionPerformed(java.awt.event.ActionEvent evt) {                                         

    MantenimientoLibro book = new MantenimientoLibro(this, true);
    book.setVisible(true);
}                                                    

   }

There are the code of the form of books.

 public class MantenimientoLibro extends javax.swing.JDialog {

  public MantenimientoLibro() {
   }

public MantenimientoLibro(java.awt.Frame parent, boolean modal) {
    super(parent, modal);
    initComponents();

    this.setLocationRelativeTo(null);
}


public MantenimientoLibro(java.awt.Dialog parent, boolean modal) {
    super(parent, modal);
    initComponents();
    this.setLocationRelativeTo(null);

}           

private void bt_salirActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:
    this.dispose();
}                                        

private void bt_insertarActionPerformed(java.awt.event.ActionEvent evt) {                                            
    // TODO add your handling code here:
    FormularioLibro formulario = new FormularioLibro(this, true);

    formulario.setVisible(true);
    this.dispose();

}                                                    

}

And this is the error i got:

Exception in thread "AWT-EventQueue-0" java.lang.RuntimeException: Uncompilable source code - Erroneous tree type: TareaP2.MantenimientoLibro
at TareaP2.VentanaPrincipal.bt_libroActionPerformed(VentanaPrincipal.java:130)
at TareaP2.VentanaPrincipal.access$100(VentanaPrincipal.java:11)
at TareaP2.VentanaPrincipal$2.actionPerformed(VentanaPrincipal.java:51)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3320)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

Answer 1

Have a look at the bug report here. It has the solution to your problem:

From the nbusers mailing list I got the following hint:

"workaround it by deselecting 'Compile On Save' in the project options".  

The answer pointed out by Mark in the comments also goes along the same line. Here is the link again: java.lang.RuntimeException: Uncompilable source code - what can cause this?

Answer 2

Exiting Netbeans and starting the compilar again resolved the issue.