Проблемы с программой javafx

Я в процессе создания настольного приложения javafx. Проблема, с которой я сталкиваюсь, заключается в том, что если я добавляю контроллер в свои файлы fxml, элементы управления каким-то образом исчезают. Программа использует плавный переход для переключения между файлами fxml.

AnchorPane reorderLevels,purchaseorder,onlineSales,generalLedger
    ,cashBook,payments,departmentalTransfers
    ,purchaseInvoice
    ,productMantainance,
    branchTransfers,stockMovement,invoiceRegistration,stockTake;

    //---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

@Override
public void initialize(URL url, ResourceBundle rb) {
    //load all the fxml screens when the buttons are clicked
    try {
        //screens for the application
         reorderLevels = FXMLLoader.load(getClass().getResource("ReorderLevels.fxml"));
         purchaseorder = FXMLLoader.load(getClass().getResource("PurchaseOrder.fxml"));
         onlineSales = FXMLLoader.load(getClass().getResource("OnlineSales.fxml"));
         generalLedger = FXMLLoader.load(getClass().getResource("GeneralLedger.fxml"));
         cashBook = FXMLLoader.load(getClass().getResource("CashBook.fxml"));
         departmentalTransfers = FXMLLoader.load(getClass().getResource("DepartmentalTransfers.fxml"));
         purchaseInvoice = FXMLLoader.load(getClass().getResource("PurchaseInvoice.fxml"));
         productMantainance = FXMLLoader.load(getClass().getResource("ProductMantainance.fxml"));
         branchTransfers = FXMLLoader.load(getClass().getResource("BranchTransfers.fxml"));
         stockMovement = FXMLLoader.load(getClass().getResource("StockMovement.fxml"));
         payments = FXMLLoader.load(getClass().getResource("Payments.fxml"));
         invoiceRegistration = FXMLLoader.load(getClass().getResource("InvoiceRegistration.fxml"));
         stockTake = FXMLLoader.load(getClass().getResource("StockTake.fxml"));
         //set each and every individual node when the buttons are clicked
         setNode(reorderLevels);


    } catch (IOException ex) {
        Logger.getLogger(FXMLDocumentController.class.getName()).log(Level.SEVERE, null, ex);

    }
}


private void setNode(Node node) {
    holderPane.getChildren().clear();
    holderPane.getChildren().add((Node) node);

    //the transition between the screens
    FadeTransition ft = new FadeTransition(Duration.millis(1));
    ft.setNode(node);
    ft.setFromValue(0.1);
    ft.setToValue(1);
    ft.setCycleCount(1);
    ft.setAutoReverse(false);
    ft.play();

}

 /* screens */



@FXML
private void switchReorderLevels(ActionEvent event) {
    setNode(reorderLevels);

}

@FXML
private void switchOnlineSales(ActionEvent event) {
    setNode(onlineSales);
}

@FXML
private void switchGeneralLedger(ActionEvent event) {
    setNode(generalLedger);
}

@FXML

private void switchPurchaseOrder(ActionEvent event) {

    setNode(purchaseorder);
}

@FXML

private void switchCashBook(ActionEvent event) {

    setNode(cashBook);
}
@FXML
private void switchAlert(ActionEvent event) {
    setNode(purchaseorder);
}


@FXML

private void switchPayments(ActionEvent event) {
    setNode(payments);
}

@FXML
private void switchDepartmentalTransfers(ActionEvent event) {
    setNode(departmentalTransfers);
}

@FXML
private void switchPurchaseInvoice(ActionEvent event) {
    setNode(purchaseInvoice);
}

@FXML
private void switchProductMantainance(ActionEvent event) {
    setNode(productMantainance);
}

@FXML
private void switchBranchTransfers(ActionEvent event) {
    setNode(branchTransfers);
} 

//this is a screen that will displayone of the layouts that will show re order levels

    <AnchorPane id = "AnchorPane" prefHeight = "713.0" prefWidth = "1219.0" style = "-fx-background-color: white;" xmlns = "http://javafx.com/javafx/9.0.1" xmlns:fx = "http://javafx.com/fxml/1">
       <children>
          <Label layoutX = "24.0" layoutY = "17.0" prefHeight = "30.0" prefWidth = "285.0" style = "-fx-font-size: 20; -fx-font-weight: bold; -fx-text-fill: #7387A8;" text = "ReOrder Levels" />
          <Separator layoutX = "25.0" layoutY = "54.0" prefHeight = "5.0" prefWidth = "1191.0" />
          <Pane fx:id = "tbl_reorderLevels" layoutX = "25.0" layoutY = "108.0" prefHeight = "413.0" prefWidth = "1174.0" style = "-fx-background-color: #EFEFEF;">
             <children>
                <JFXComboBox fx:id = "cmd_reOrder_productCode" layoutX = "48.0" layoutY = "33.0" prefHeight = "25.0" prefWidth = "267.0" promptText = "Product Code" />
                <JFXTextField fx:id = "txt_reOrder_reorderLevel" labelFloat = "true" layoutX = "48.0" layoutY = "91.0" prefHeight = "25.0" prefWidth = "267.0" promptText = "Reorder Level" />

// это корневой макет, в котором есть кнопки, которые будут перемещаться между экранами с помощью плавного перехода

<?xml version = "1.0" encoding = "UTF-8"?>

<?import com.jfoenix.controls.JFXButton?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.effect.InnerShadow?>
<?import javafx.scene.image.Image?>
<?import javafx.scene.image.ImageView?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.Pane?>
<?import javafx.scene.layout.VBox?>
<?import javafx.scene.text.Font?>

<!-- root layout -->

<AnchorPane id = "AnchorPane" nodeOrientation = "LEFT_TO_RIGHT" prefHeight = "623.0" prefWidth = "1271.0" style = "-fx-background-color: #fff;" xmlns = "http://javafx.com/javafx/9.0.1" xmlns:fx = "http://javafx.com/fxml/1" fx:controller = "dashboard.FXMLDocumentController">
   <children>
      <Pane layoutX = "-2.0" prefHeight = "81.0" prefWidth = "1272.0" style = "-fx-background-color: #0b8dee;" styleClass = "head-background" stylesheets = "@style.css" AnchorPane.leftAnchor = "0.0" AnchorPane.rightAnchor = "0.0" AnchorPane.topAnchor = "0.0">
         <children>
            <Label fx:id = "labelEstock" layoutX = "204.0" layoutY = "-3.0" prefHeight = "88.0" prefWidth = "536.0" style = "-fx-shape: round;" stylesheets = "@custom.css" text = "Oasys Estock" textFill = "WHITE">
               <font>
                  <Font name = "Brush Script MT Italic" size = "36.0" />
               </font>
            </Label>
           <!-- <ImageView fx:id = "imageEstock" fitHeight = "110.0" fitWidth = "92.0" layoutX = "102.0" layoutY = "8.0" pickOnBounds = "true" preserveRatio = "true">
               <image>
                  <Image 

    url = "@../../../../AndroidStudioProjects/OasysEstock/app/src/main/res/drawable/fortified_icon.png" />
                   </image>
                </ImageView> --> 
             </children>
          </Pane>
          <VBox layoutY = "85.0" maxHeight = "-Infinity" maxWidth = "-Infinity" minHeight = "-Infinity" minWidth = "-Infinity" prefHeight = "518.0" prefWidth = "122.0" style = "-fx-background-color: #0b8dee; -fx-background-radius: 15;">
             <children>
                <JFXButton id = "btnReorderLevels" fx:id = "btnReorderLevels" buttonType = "RAISED" maxWidth = "-Infinity" minHeight = "-Infinity" minWidth = "-Infinity" onAction = "#switchReorderLevels" prefHeight = "47.0" prefWidth = "107.0" style = "-fx-background-radius: 100;" text = "ReOrder Levels" textFill = "#f5f0f0">
                   <VBox.margin>
                      <Insets />
                   </VBox.margin>
                   <font>
                      <Font name = "Calibri" size = "12.0" />
                   </font>
                </JFXButton>
                <JFXButton fx:id = "btnInvoiceRegistration" onAction = "#switchInvoiceRegistration" prefHeight = "25.0" prefWidth = "121.0" text = "Invoice Registration" textFill = "#f8f4f4" />
                <JFXButton fx:id = "btnPurchaseOrder" buttonType = "RAISED" onAction = "#switchPurchaseOrder" prefHeight = "34.0" prefWidth = "107.0" text = "Purchase Order" textFill = "#f5f0f0">
                   <font>
                      <Font name = "Cambria" size = "12.0" />
                   </font>
                </JFXButton>
                <JFXButton fx:id = "btnOnlineSales" onAction = "#switchOnlineSales" prefHeight = "39.0" prefWidth = "107.0" text = "Online Sales" textFill = "#fff9f9">
                   <font>
                      <Font name = "Calibri" size = "12.0" />
                   </font>
                </JFXButton>
                <JFXButton fx:id = "btnGeneralLedger" onAction = "#switchGeneralLedger" prefHeight = "40.0" prefWidth = "108.0" text = "General Ledger" textFill = "#f2eeee" />
                <JFXButton fx:id = "btnCashBook" onAction = "#switchCashBook" prefHeight = "35.0" prefWidth = "104.0" text = "Cash Book" textFill = "#fffefe" />
                <JFXButton fx:id = "btnPayments" buttonType = "RAISED" onAction = "#switchPayments" prefHeight = "25.0" prefWidth = "114.0" text = "Payments" textFill = "#fcf6f6" />
                <JFXButton fx:id = "btnDepartmentalTransfers" buttonType = "RAISED" layoutX = "10.0" layoutY = "205.0" onAction = "#switchDepartmentalTransfers" prefHeight = "25.0" prefWidth = "114.0" text = "Dept Transfers" textFill = "#fcf6f6" />
                <JFXButton fx:id = "btnProductMantainance" buttonType = "RAISED" layoutX = "10.0" layoutY = "230.0" onAction = "#switchProductMantainance" prefHeight = "56.0" prefWidth = "121.0" text = "Product Mantainance" textFill = "#fcf6f6">
                   <font>
                      <Font size = "11.0" />
                   </font>
                </JFXButton>
                <JFXButton fx:id = "btnPurchaseInvoice" buttonType = "RAISED" layoutX = "10.0" layoutY = "255.0" onAction = "#switchPurchaseInvoice" prefHeight = "56.0" prefWidth = "121.0" text = "Purchase Invoice" textFill = "#fcf6f6">
                   <font>
                      <Font size = "11.0" />
                   </font>
                </JFXButton>
                <JFXButton fx:id = "btnBranchTransfers" buttonType = "RAISED" layoutX = "10.0" layoutY = "311.0" onAction = "#switchBranchTransfers" prefHeight = "56.0" prefWidth = "121.0" text = "Branch Transfers" textFill = "#fcf6f6">
                   <font>
                      <Font size = "11.0" />
                   </font>
                </JFXButton>
                <JFXButton fx:id = "btnStockMovement" buttonType = "RAISED" layoutX = "10.0" layoutY = "367.0" onAction = "#switchStockMovement" prefHeight = "56.0" prefWidth = "121.0" text = "Stock Movement" textFill = "#fcf6f6">
                   <font>
                      <Font size = "11.0" />
                   </font>
                </JFXButton>
                <JFXButton fx:id = "btnStockTake" buttonType = "RAISED" layoutX = "10.0" layoutY = "448.0" onAction = "#switchStockTake" prefHeight = "56.0" prefWidth = "121.0" text = "Stock Take" textFill = "#fcf6f6">
                   <font>
                      <Font size = "11.0" />
                   </font>
                </JFXButton>
             </children>
             <effect>
                <InnerShadow blurType = "TWO_PASS_BOX" choke = "0.58" color = "#212122" height = "26.69" radius = "10.620000000000001" width = "17.79" />
             </effect>
          </VBox>
          <AnchorPane fx:id = "holderPane" layoutX = "125.0" layoutY = "96.0" prefHeight = "507.0" prefWidth = "1134.0"/>
       </children>
    </AnchorPane>