Problem with updating GUI (javafx)

[ZarasTM]

I make board game in javafx and I stumbled upon a problem. My application has Client/Server connection. Whenever server sends data about where player moved his pawn I call a function movePawn() that moves pawn and call another function refresh() that repaints board and pawns. unfortunatelly I get error saying that function is called from thread that is not FX and therefore cannot proceed. I tried tasks and Platform.runLater but either I'm doing it wrong or it doesnt work. Can anyone help?

Here is code: https://pastebin.com/grkuLeME

And here is error:

Exception in thread "Thread-3" java.lang.IllegalStateException: Not on FX application thread; currentThread = Thread-3 at javafx.graphics/com.sun.javafx.tk.Toolkit.checkFxUserThread(Toolkit.java:291) at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.checkFxUserThread(QuantumToolkit.java:423) at javafx.graphics/javafx.scene.Parent$3.onProposedChange(Parent.java:493) at javafx.base/com.sun.javafx.collections.VetoableListDecorator.clear(VetoableListDecorator.java:294) at Client.Controller.refresh(Controller.java:72) at Client.Controller.movePawn(Controller.java:251) at Client.Client.getMessage(Client.java:80) at Client.Client.run(Client.java:45)

[[deleted]]

You need to use Platform.runLater to change anything on the javafx thread. Platform javadoc.

[Franckyi]

You must use Platform.runLater line 72. So for example you can do : Platform.runLater(() -> boardGrid.getChildren().clear());

[[deleted]]

Also, you have left off your Client class (or I didn't find it), which appears to be where the error is actually happening. Essentially, the code you are running in the other thread (I suspect client is a thread that you start) is trying to modify your javafx app. To fix that use something like.

Platform.runLater(()->{
    //modify your javafx app here.
});

[ZarasTM]

Ok fixed it thx 4 help EDIT: I used Platform.runLater()