ADDITIONAL SYSTEM INFORMATION :
Linux Mint 19

A DESCRIPTION OF THE PROBLEM :
The startDragAndDrop method no longer works with GTK3

REGRESSION : Last worked in version 10.0.2

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the source code and try to drag from the test button. Nothing is happening...

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The possibility of dragging
ACTUAL -
Nothing is happening.

---------- BEGIN SOURCE ----------
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.TransferMode;
import javafx.stage.Stage;

//Workaround: -Djdk.gtk.version=2
public class Fx11draggError extends Application{

@Override
public void start(Stage stage) throws Exception {
Button button = new Button("test");
button.setOnDragDetected(e -> {
ClipboardContent content = new ClipboardContent();
content.putString("It works");
button.startDragAndDrop(TransferMode.MOVE).setContent(content);
e.consume();
});
stage.setScene(new Scene(button, 200, 200));
stage.show();
}

public static void main(String[] args) {
launch();
}
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
use -Djdk.gtk.version=2

FREQUENCY : always