JavaFX launch(args) method throws java.lang.reflect.InvocationTargetException, java.lang.NullPointerException - javafx

Question

So I was trying to launch my JavaFX application and a stack trace error showed up:
Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)
Caused by: java.lang.NullPointerException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplication(Unknown Source)
And I wondered what was going. At the bottom of the stack trace it says there's a NullPointer at the launch(args) method. I tried everything but I couldn't get it to work. This is my code:
public class Main extends Application{
public void main(String[] args){
launch(args);
}
//START
//GUI
#Override
public void start(Stage primarystage) throws Exception {
SplitPane fullpane = new SplitPane();
//DECK
ScrollPane deckscrollpane = new ScrollPane();
AnchorPane deck = new AnchorPane();
deck.setOnMouseClicked((e)->{
System.out.println(e.getSceneX());
System.out.println(e.getSceneY());
});
Rectangle rec = new Rectangle();
rec.setTranslateX(23);
rec.setTranslateY(20);
rec.setWidth(200);
rec.setHeight(300);
deck.getChildren().add(rec);
deckscrollpane.setContent(deck);
//MAP
StackPane map = new StackPane();
fullpane.getItems().addAll(deckscrollpane, map);
fullpane.setDividerPositions(0.4f, 0.6f);
Scene scn = new Scene(fullpane, 700, 700);
primarystage.setScene(scn);
primarystage.show();
}
}
I'm pretty new to JavaFX, and I was hoping someone fairly experienced can explain how I'm supposed to fix this. My IDE (Eclipse) isn't showing any errors in the code either. The error only pops up when I run the program. I installed the JavaFX plugin (I think it's called something like e(fx)clipse or somethin' like that). A little help?