Index: src/org/openstreetmap/josm/plugins/javafx/gui/JavaFxWrapper.java
===================================================================
--- src/org/openstreetmap/josm/plugins/javafx/gui/JavaFxWrapper.java	(revision 35423)
+++ src/org/openstreetmap/josm/plugins/javafx/gui/JavaFxWrapper.java	(working copy)
@@ -2,6 +2,8 @@
 package org.openstreetmap.josm.plugins.javafx.gui;
 
 import java.awt.Dimension;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.FutureTask;
 
 import org.openstreetmap.josm.tools.Logging;
 
@@ -61,14 +63,24 @@
      */
     private void initialize(T node) {
         this.node = node;
-        Platform.runLater(this::initFX);
+        FutureTask<Scene> task = new FutureTask<>(this::initFX);
+        Platform.runLater(task);
         Platform.setImplicitExit(false);
         this.setFocusTraversalKeysEnabled(node.isFocusTraversable());
+        try {
+            task.get();
+        } catch (InterruptedException | ExecutionException e) {
+            Logging.error(e);
+        }
     }
 
-    private void initFX() {
+    /**
+     * @return The scene to be used for initializing JavaFX
+     */
+    protected Scene initFX() {
         Scene scene = createScene();
         setScene(scene);
+        return scene;
     }
 
     private Scene createScene() {