Fix

src/App/Scenes/StageInitializer.java

@@ -88,12 +88,8 @@ public class StageInitializer {
      * Sets main menu scene.
      */
     static void setMainMenuScene() {
-        try {
             MainMenu mainMenu = new MainMenu();
             stage.setScene(mainMenu.getScene());
-        } catch (ConcurrentModificationException e) {
-            System.out.println("Nora er kul");
-        }
     }
 
     /**