javafx onaction not in the namespace

[Linuxuser1234]

trying to make a popup window but when i run it i get this error hadn't find any working solutions yet
"C:\Program Files\Java\jdk-18.0.1\bin\java.exe" "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2022.1.2\lib\idea_rt.jar=64045:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2022.1.2\bin" -Dfile.encoding=UTF-8 -classpath C:\Users\awips\.m2\repository\org\openjfx\javafx-controls\18\javafx-controls-18.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-graphics\18\javafx-graphics-18.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-base\18\javafx-base-18.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-fxml\18\javafx-fxml-18.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-web\18\javafx-web-18.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-media\18\javafx-media-18.jar -p C:\Users\awips\.m2\repository\org\openjfx\javafx-fxml\18\javafx-fxml-18-win.jar;C:\Users\awips\.m2\repository\org\kordamp\ikonli\ikonli-javafx\12.3.0\ikonli-javafx-12.3.0.jar;C:\Users\awips\.m2\repository\eu\hansolo\tilesfx\11.48\tilesfx-11.48.jar;C:\Users\awips\IdeaProjects\bolt\boltgui\target\classes;C:\Users\awips\.m2\repository\org\kordamp\bootstrapfx\bootstrapfx-core\0.4.0\bootstrapfx-core-0.4.0.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-controls\18\javafx-controls-18-win.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-base\18\javafx-base-18-win.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-graphics\18\javafx-graphics-18-win.jar;C:\Users\awips\.m2\repository\org\controlsfx\controlsfx\11.1.1\controlsfx-11.1.1.jar;C:\Users\awips\.m2\repository\com\dlsc\formsfx\formsfx-core\11.3.2\formsfx-core-11.3.2.jar;C:\Users\awips\.m2\repository\org\kordamp\ikonli\ikonli-core\12.3.0\ikonli-core-12.3.0.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-media\18\javafx-media-18-win.jar;C:\Users\awips\.m2\repository\org\openjfx\javafx-web\18\javafx-web-18-win.jar;C:\Users\awips\.m2\repository\net\synedra\validatorfx\0.2.1\validatorfx-0.2.1.jar -m com.bolt.boltgui/com.bolt.boltgui.boltgui Exception in Application start method java.lang.reflect.InvocationTargetException at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:119) at java.base/java.lang.reflect.Method.invoke(Method.java:577) at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:465) at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:364) at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104) at java.base/java.lang.reflect.Method.invoke(Method.java:577) at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1081) Caused by: java.lang.RuntimeException: Exception in Application start method at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:901) at javafx.graphics@18/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:196) at java.base/java.lang.Thread.run(Thread.java:833) Caused by: javafx.fxml.LoadException: Error resolving onAction='#Popup1', either the event handler is not in the Namespace or there is an error in the script.
`package com.bolt.boltgui;
import java.io.IOException;
import java.net.URL;
import java.util.Objects;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.stage.*;
public class ButtonController implements Initializable{
@FXML
private Button Skewt;
@OverRide
public void initialize(URL location, ResourceBundle resources) {
}
@FXML
private void Skewt(ActionEvent event) throws IOException {
Parent SkewtParent = FXMLLoader.load((URL) Objects.requireNonNull(Skewtplotter.getResource("Skewtplotter.fxml")));
Scene Scene = new Scene(SkewtParent);
Stage popup1 = new Stage();
popup1.setScene(Scene);
Skewt.setOnAction((EventHandler) event);
popup1.show();

}

}`
and on the ActionEvent i replaced event with Popup1 and Skewt.setOnAction((EventHandler) event); with Popup1 it still wouldn't work i changed it back to event