TypeError : Cannot read property 'initLazy' of undefined?

I'm a newbie to Vaadin development. try to set up a project for Wildfly. I am using Vaadin 14.1.16 with Wildfly 18 and Java 8. I get an error on the page when I load the page as below.

(TypeError) : Cannot read property 'initLazy' of undefined

Also, the textArea does not appear on the page.

The comment label is on the right side while I expected to be under the select component. I have already tried on google to find anything related to this issue but nothing onboard.

Vaadin genius, do you have any idea why and how should I solve it?

@Route(value = "maintenance", layout = MainView.class)
@PageTitle("Maintenance Mode Selector")
public class MaintenanceView extends Div implements AfterNavigationObserver {

    @Inject
    private Maintenance maintenance;
    private ComboBox<MaintenanceMode> operationComboBox = new ComboBox<>(MaintenanceMode.NORMAL_OPERATION.getDescription());
    private Select<String> maintenanceSelector = new Select();
    private TextArea commentTextArea = new TextArea();
    private PasswordField passwordField = new PasswordField();
    private Button btnOperation = new Button("Set Operation Mode");

    public MaintenanceView() {
        setId("maintenance-view");

        operationComboBox.setItemLabelGenerator(MaintenanceMode::getDescription);
        operationComboBox.setItems(MaintenanceMode.values());

        maintenanceSelector.setItems("MAINTENANCE OPERATION", "NORMAL OPERATION");
        maintenanceSelector.getStyle().set("width", "40em");
        maintenanceSelector.setPlaceholder("CHOOSE AN OPERATION");

        commentTextArea.getStyle().set("minHeight", "200em");
        commentTextArea.setPlaceholder("Down time is expected to be 30 minute ...");
        commentTextArea.addThemeVariants(TextAreaVariant.LUMO_SMALL);

        btnOperation.addThemeVariants(ButtonVariant.LUMO_PRIMARY);
        btnOperation.addClickListener(buttonClickEvent -> {
            maintenance.setMode("MAINTENANCE OPERATION".equals(maintenanceSelector.getValue()) ? "1" : "0");
            maintenance.setComment(commentTextArea.getValue());
        });

        SplitLayout splitLayout = new SplitLayout();
        splitLayout.setOrientation(SplitLayout.Orientation.HORIZONTAL);
        splitLayout.setSizeFull();

        createEditorLayout(splitLayout);

        add(splitLayout);
    }


    private void createEditorLayout(SplitLayout splitLayout) {
        FormLayout formLayout = new FormLayout();
        formLayout.setResponsiveSteps(
                new FormLayout.ResponsiveStep("40em",2, FormLayout.ResponsiveStep.LabelsPosition.TOP),
                new FormLayout.ResponsiveStep("40em",1, FormLayout.ResponsiveStep.LabelsPosition.TOP),
                new FormLayout.ResponsiveStep("40em",2, FormLayout.ResponsiveStep.LabelsPosition.TOP),
                new FormLayout.ResponsiveStep("40em",1, FormLayout.ResponsiveStep.LabelsPosition.TOP)
                );

        formLayout.addFormItem( operationComboBox, "Combobox Component:");
        formLayout.addFormItem( maintenanceSelector, "Select Component:");
        formLayout.addFormItem( commentTextArea, "Comments:");
        formLayout.addFormItem( passwordField, "Password:");
        formLayout.addFormItem( btnOperation,"");

        formLayout.setColspan(operationComboBox,2);
        formLayout.setColspan(maintenanceSelector,2);
        formLayout.setColspan(commentTextArea,2);
        formLayout.setColspan(passwordField,2);
        formLayout.setColspan(btnOperation,1);

        splitLayout.addToSecondary(formLayout);
    }

    @Override
    public void afterNavigation(AfterNavigationEvent afterNavigationEvent) {

    }
}   

I changed the layout a little bit but I get now these errors.

(TypeError) : Cannot read property 'confirm' of undefined
(TypeError) : Cannot read property 'set' of undefined
(TypeError) : Cannot read property 'updateSize' of undefined

The page screenshot.

After communication with people from Vaadin, they advise me the following:

Hi! looks like the front-end bundle hasn't updated; 
after adding the combobox to the view, did you restart the app? 
Vaadin needs to run mvn Vaadin:prepare-frontend to include the new component.

And I did the following after that problem solved unexpectedly. thanks to all of you for your kind replay.

1- stop wildfly

2- maven:clean

3-vaadin:war

4- restarted server wildfly.