When I'm trying to add new obj to scene.content, I get an exception:
init:
deps-jar:
compile:
jar:
standard-run:
sceneContent -> SwingTextFieldTextSwingButtonText
textObjSeq -> Text
Text with title'sgsdgf' has been added.
Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
        at com.sun.embeddedswing.EmbeddedEventQueue.moveToVisibleAndOnScreen(EmbeddedEventQueue.java:155)
        at com.sun.embeddedswing.EmbeddedEventQueue.beforeDispatch(EmbeddedEventQueue.java:376)
        at com.sun.embeddedswing.EmbeddedEventQueue.dispatchEvent(EmbeddedEventQueue.java:439)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)


The code:
package default;

import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.text.Text;
import javafx.ext.swing.SwingTextField;
import javafx.ext.swing.SwingButton;
import javafx.scene.input.MouseEvent;
import javafx.scene.Node;

var textObjSeq : Text[] = [];

var textBoxTitle : Text = Text{
     layoutX: 20
     layoutY: 20
     content: "Enter title"
}

 var textBox : SwingTextField = SwingTextField{
    columns: 4
    layoutX: 20
    layoutY: 25
}

var button : SwingButton = SwingButton{
    layoutX: 85
    layoutY: 24
    text: "create new Text-type object"
    onMouseClicked:function(event : MouseEvent):Void{
        var title = textBox.text;
        if(title != null and title.trim().length() > 0){
            addNewText(title);
        }
    }
}

function addNewText(title:String): Void{
    var yPos:Integer = 80 + 30*textObjSeq.size();
    var txt = Text{
        content: title
        layoutX: 20
        layoutY: yPos;
        onMouseClicked: function(event : MouseEvent){
            println("textObjSeq before deleting element {textObjSeq}");
            delete event.node as Text from textObjSeq;
            delete event.node from sceneContent;
            println("textObjSeq after deleting element {textObjSeq}");
        }
    }
    insert txt into textObjSeq;
    //insert txt into stage.scene.content; //the same thing happens
    insert txt into sceneContent;
    
    println("sceneContent -> {sceneContent}");
    println("textObjSeq -> {textObjSeq}");
    println("Text with title'{title}' has been added.");
}

var sceneContent : Node[] = [textBox, textBoxTitle, button];

var stage : Stage = Stage {
    title: "Creating text"
    width: 400
    height: 400
    scene: Scene {
        content: bind sceneContent
    }
}