title: "FXMLLoader.constructLoadException" when trying to run java fx application
body: <p>I already searched the deepest depths of the interweb but no answer will seem to be found -.- </p>
  
  <p>The problem is in my javaFx programm i want to write. But i can't make it any further than adding the controller class. I followed nearly every tutorial a could find, but the issue still remains unknown to me.</p>
  
  <p>This is the exception:</p>
  
  <pre><code>javafx.fxml.LoadException: 
  /U:/BankingSolutions/MediaCenterFX/bin/main/ressources/view/MainUI.fxml:12
  
  at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2617)
  at javafx.fxml.FXMLLoader.access$700(FXMLLoader.java:104)
  at javafx.fxml.FXMLLoader$ValueElement.processAttribute(FXMLLoader.java:927)
  at javafx.fxml.FXMLLoader$InstanceDeclarationElement.processAttribute(FXMLLoader.java:976)
  at javafx.fxml.FXMLLoader$Element.processStartElement(FXMLLoader.java:216)
  at javafx.fxml.FXMLLoader$ValueElement.processStartElement(FXMLLoader.java:738)
  at javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2723)
  at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2527)
  at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
  at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3230)
  at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3191)
  at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3164)
  at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3140)
  at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3120)
  at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3113)
  at application.Main.start(Main.java:15)
  at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
  at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
  at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
  at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
  at java.security.AccessController.doPrivileged(Native Method)
  at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
  at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
  at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
  at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
  at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
  at java.lang.Thread.run(Thread.java:745)
  Caused by: java.lang.ClassNotFoundException: /java/controllers/MainUIController
  at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
  at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
  at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
  at javafx.fxml.FXMLLoader$ValueElement.processAttribute(FXMLLoader.java:925)
  ... 24 more
  </code></pre>
  
  <p>and this is the code. there are thre classes: The Main.class, my MainUI.fxml which i created using scenebuilder 2 and my MainUIController.class which should obviously work as the mainuis controller</p>
  
  <pre><code>package application;
  
  import javafx.application.Application;
  import javafx.fxml.FXMLLoader;
  import javafx.stage.Stage;
  import javafx.scene.Scene;
  import javafx.scene.layout.AnchorPane;
  
  
  public class Main extends Application {
  
      @Override
      public void start(Stage primaryStage) {
          try {
              AnchorPane root = (AnchorPane) FXMLLoader.load(getClass().getResource("/main/ressources/view/MainUI.fxml"));
              Scene scene = new Scene(root);
              primaryStage.setScene(scene);
              primaryStage.show();
  
          } catch(Exception e) {
              e.printStackTrace();
          }
      }
  
      public static void main(String[] args) {
          launch(args); 
      }
  }
  
  _______________________________________________
  
  &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  
  &lt;?import javafx.scene.text.*?&gt;
  &lt;?import javafx.scene.control.*?&gt;
  &lt;?import javafx.scene.*?&gt;
  &lt;?import javafx.geometry.*?&gt;
  &lt;?import javafx.scene.image.*?&gt;
  &lt;?import java.lang.*?&gt;
  &lt;?import javafx.scene.layout.*?&gt;
  &lt;?import javafx.scene.layout.AnchorPane?&gt;
  
  &lt;AnchorPane fx:id="root" prefHeight="1080.0" prefWidth="1920.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="/java/controllers/MainUIController"&gt;
     &lt;children&gt;
        &lt;BorderPane fx:id="borderPane01" layoutX="657.0" layoutY="304.0" prefHeight="336.0" prefWidth="403.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0"&gt;
           &lt;bottom&gt;
              &lt;AnchorPane fx:id="bp_bottom" prefHeight="200.0" prefWidth="200.0" BorderPane.alignment="CENTER" /&gt;
           &lt;/bottom&gt;
           &lt;left&gt;
              &lt;GridPane fx:id="bp_left_grid" prefHeight="680.0" prefWidth="238.0" BorderPane.alignment="CENTER"&gt;
                &lt;columnConstraints&gt;
                    &lt;ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" /&gt;
                  &lt;ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" /&gt;
                  &lt;ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" /&gt;
                &lt;/columnConstraints&gt;
                &lt;rowConstraints&gt;
                    &lt;RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /&gt;
                    &lt;RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /&gt;
                    &lt;RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /&gt;
                  &lt;RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /&gt;
                  &lt;RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /&gt;
                  &lt;RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /&gt;
                    &lt;RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" /&gt;
                &lt;/rowConstraints&gt;
                 &lt;children&gt;
                    &lt;Button fx:id="btn_search" mnemonicParsing="false" prefHeight="48.0" prefWidth="172.0" text="Suche" GridPane.columnSpan="2147483647" GridPane.halignment="CENTER" GridPane.hgrow="ALWAYS" GridPane.valignment="CENTER"&gt;
                       &lt;GridPane.margin&gt;
                          &lt;Insets /&gt;
                       &lt;/GridPane.margin&gt;
                       &lt;font&gt;
                          &lt;Font size="24.0" /&gt;
                       &lt;/font&gt;
                    &lt;/Button&gt;
                    &lt;Button fx:id="btn_series" mnemonicParsing="false" prefHeight="48.0" prefWidth="172.0" text="Serien" wrapText="true" GridPane.columnSpan="3" GridPane.halignment="CENTER" GridPane.rowIndex="1" GridPane.valignment="CENTER"&gt;
                       &lt;font&gt;
                          &lt;Font size="24.0" /&gt;
                       &lt;/font&gt;
                    &lt;/Button&gt;
                    &lt;Button fx:id="btn_download" mnemonicParsing="false" prefHeight="48.0" prefWidth="172.0" text="Download" GridPane.columnSpan="3" GridPane.halignment="CENTER" GridPane.rowIndex="3" GridPane.valignment="CENTER"&gt;
                       &lt;font&gt;
                          &lt;Font size="24.0" /&gt;
                       &lt;/font&gt;
                    &lt;/Button&gt;
                    &lt;Button fx:id="btn_movies" mnemonicParsing="false" prefHeight="48.0" prefWidth="172.0" text="Filme" wrapText="true" GridPane.columnSpan="3" GridPane.halignment="CENTER" GridPane.rowIndex="2" GridPane.valignment="CENTER"&gt;
                       &lt;font&gt;
                          &lt;Font size="24.0" /&gt;
                       &lt;/font&gt;
                    &lt;/Button&gt;
                    &lt;Button fx:id="btn_exit" mnemonicParsing="false" prefHeight="48.0" prefWidth="172.0" text="Beenden" GridPane.columnSpan="3" GridPane.halignment="CENTER" GridPane.rowIndex="6" GridPane.valignment="CENTER"&gt;
                       &lt;font&gt;
                          &lt;Font size="24.0" /&gt;
                       &lt;/font&gt;
                    &lt;/Button&gt;
                    &lt;Button fx:id="btn_settings" mnemonicParsing="false" prefHeight="48.0" prefWidth="172.0" text="Optionen" GridPane.columnSpan="3" GridPane.halignment="CENTER" GridPane.rowIndex="4" GridPane.valignment="CENTER"&gt;
                       &lt;font&gt;
                          &lt;Font size="24.0" /&gt;
                       &lt;/font&gt;
                    &lt;/Button&gt;
                    &lt;Button fx:id="btn_dashboard" mnemonicParsing="false" prefHeight="48.0" prefWidth="172.0" text="Dashboard" GridPane.columnSpan="3" GridPane.halignment="CENTER" GridPane.rowIndex="5" GridPane.valignment="CENTER"&gt;
                       &lt;font&gt;
                          &lt;Font size="24.0" /&gt;
                       &lt;/font&gt;
                    &lt;/Button&gt;
  
                 &lt;/children&gt;
              &lt;/GridPane&gt;
           &lt;/left&gt;
           &lt;top&gt;
              &lt;AnchorPane fx:id="bp_top" prefHeight="200.0" prefWidth="200.0" BorderPane.alignment="CENTER"&gt;
                 &lt;children&gt;
                    &lt;Label fx:id="headlabel" alignment="CENTER" layoutX="737.0" layoutY="92.0" prefHeight="200.0" prefWidth="1920.0" text="Dashboard" textAlignment="CENTER" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0"&gt;
                       &lt;font&gt;
                          &lt;Font size="48.0" /&gt;
                       &lt;/font&gt;
                    &lt;/Label&gt;
                 &lt;/children&gt;
              &lt;/AnchorPane&gt;
           &lt;/top&gt;
           &lt;center&gt;
              &lt;AnchorPane fx:id="bp_center" prefHeight="200.0" prefWidth="200.0" BorderPane.alignment="CENTER" /&gt;
           &lt;/center&gt;
           &lt;right&gt;
              &lt;AnchorPane fx:id="bp_right" prefHeight="200.0" prefWidth="200.0" BorderPane.alignment="CENTER" /&gt;
           &lt;/right&gt;
        &lt;/BorderPane&gt;
     &lt;/children&gt;
  &lt;/AnchorPane&gt;
  
  ______________________________________________
  
  package main.java.controllers;
  
  import java.net.URL;
  import java.util.ResourceBundle;
  
  import javafx.fxml.FXML;
  import javafx.scene.control.Button;
  import javafx.scene.control.Label;
  import javafx.scene.layout.AnchorPane;
  import javafx.scene.layout.BorderPane;
  import javafx.scene.layout.GridPane;
  
  public class MainUIController{
  
      @FXML // ResourceBundle that was given to the FXMLLoader
      private ResourceBundle resources;
  
      @FXML // URL location of the FXML file that was given to the FXMLLoader
      private URL location;
  
      @FXML // fx:id="btn_search"
      private Button btn_search; // Value injected by FXMLLoader
  
      @FXML // fx:id="btn_movies"
      private Button btn_movies; // Value injected by FXMLLoader
  
      @FXML // fx:id="btn_exit"
      private Button btn_exit; // Value injected by FXMLLoader
  
      @FXML // fx:id="btn_series"
      private Button btn_series; // Value injected by FXMLLoader
  
      @FXML // fx:id="bp_right"
      private AnchorPane bp_right; // Value injected by FXMLLoader
  
      @FXML // fx:id="bp_bottom"
      private AnchorPane bp_bottom; // Value injected by FXMLLoader
  
      @FXML // fx:id="borderPane01"
      private BorderPane borderPane01; // Value injected by FXMLLoader
  
      @FXML // fx:id="headlabel"
      private Label headlabel; // Value injected by FXMLLoader
  
      @FXML // fx:id="bp_left_grid"
      private GridPane bp_left_grid; // Value injected by FXMLLoader
  
      @FXML // fx:id="bp_top"
      private AnchorPane bp_top; // Value injected by FXMLLoader
  
      @FXML // fx:id="root"
      private AnchorPane root; // Value injected by FXMLLoader
  
      @FXML // fx:id="btn_download"
      private Button btn_download; // Value injected by FXMLLoader
  
      @FXML // fx:id="btn_dashboard
      private Button btn_dashboard; // Value injected by FXMLLoader
  
      @FXML // fx:id="bp_center"
      private AnchorPane bp_center; // Value injected by FXMLLoader
  
      @FXML // fx:id="btn_settings"
      private Button btn_settings; // Value injected by FXMLLoader
  
      @FXML // This method is called by the FXMLLoader when initialization is complete
      void initialize() {
          assert root         != null : "fx:id=\"root\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert borderPane01 != null : "fx:id=\"borderPane01\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert bp_top       != null : "fx:id=\"bp_top\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert headlabel    != null : "fx:id=\"headlabel\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert bp_left_grid != null : "fx:id=\"bp_left_grid\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert bp_center    != null : "fx:id=\"bp_center\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert bp_right     != null : "fx:id=\"bp_right\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert bp_bottom    != null : "fx:id=\"bp_bottom\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert btn_search   != null : "fx:id=\"btn_search\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert btn_series   != null : "fx:id=\"btn_series\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert btn_movies   != null : "fx:id=\"btn_movies\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert btn_download != null : "fx:id=\"btn_download\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert btn_settings != null : "fx:id=\"btn_settings\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert btn_dashboard!= null : "fx:id=\"dashboard\" was not injected: check your FXML file 'MainUI.fxml'.";
          assert btn_exit     != null : "fx:id=\"btn_exit\" was not injected: check your FXML file 'MainUI.fxml'.";
  
          btn_search.setOnAction(value -&gt; {
              System.out.println("Search pressed"); //TODO
          });
          btn_series.setOnAction(value -&gt;{
              System.out.println("series pressed");
          });
          btn_movies.setOnAction(value -&gt;{
              System.out.println("movies pressed");
          });
          btn_download.setOnAction(value -&gt;{
              System.out.println("download pressed");
          });
          btn_settings.setOnAction(value -&gt;{
              System.out.println("settings pressed");
          });
          btn_dashboard.setOnAction(value -&gt;{
              System.out.println("dashboard pressed");
          });
          btn_exit.setOnAction(value -&gt;{
              System.out.println("exit pressed");
          });
  
  
      }
  }
  </code></pre>
  
  <p><strong>Edit:</strong> Here is my package structure:</p>
  
  <pre><code>src
  |-application
      |here is my main application
  |-main
      |-java
          |-controllers
              |here are my controllers
          |-dao
          |-service
      |-ressources
          |-css
          |-images
          |-view
             |here are the fxml files
  </code></pre>