Spotted in our nightly CI test build:

NodeInitializationStressTest > menuBar() STANDARD_ERROR
    java.util.ConcurrentModificationException
     at java.base/java.util.WeakHashMap$HashIterator.nextEntry(WeakHashMap.java:816)
     at java.base/java.util.WeakHashMap$EntryIterator.next(WeakHashMap.java:855)
     at java.base/java.util.WeakHashMap$EntryIterator.next(WeakHashMap.java:853)
     at javafx.controls@25-ea/javafx.scene.control.skin.MenuBarSkin.cleanUpSystemMenu(MenuBarSkin.java:1037)
     at javafx.controls@25-ea/javafx.scene.control.skin.MenuBarSkin.dispose(MenuBarSkin.java:668)
     at javafx.controls@25-ea/javafx.scene.control.Control$2.invalidated(Control.java:273)
     at javafx.base@25-ea/javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
     at javafx.base@25-ea/javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:147)
     at javafx.graphics@25-ea/javafx.css.StyleableObjectProperty.set(StyleableObjectProperty.java:256)
     at javafx.controls@25-ea/javafx.scene.control.Control.setSkin(Control.java:240)
     at test.robot.javafx.scene.NodeInitializationStressTest.lambda$menuBar$72(NodeInitializationStressTest.java:757)
     at test.robot.javafx.scene.NodeInitializationStressTest.lambda$test$165(NodeInitializationStressTest.java:1479)
     at java.base/java.lang.Thread.run(Thread.java:1575)

NodeInitializationStressTest > menuBar() FAILED
    org.opentest4j.AssertionFailedError
        at app//org.junit.jupiter.api.AssertionUtils.fail(AssertionUtils.java:34)
        at app//org.junit.jupiter.api.Assertions.fail(Assertions.java:119)
        at app//test.robot.javafx.scene.NodeInitializationStressTest.afterEach(NodeInitializationStressTest.java:1839)