Copy command fails when selected object contains references

1) Start SB
2) Open FXOMClonerTest.fxml (attached)
3) Select Label with text = "Header Label (Same Font as Title Label)"
4) Edit -> Copy
5) Open a Text Editor
6) Paste in the Text Editor
    => the path of the FXOMClonerTest.fxml is pasted
    => BUG: the FXML text of the copied Label should be pasted


In SB log file, we can see the following exception thrown at step #4:

com.oracle.javafx.scenebuilder.app.SceneBuilderApp$SceneBuilderUncaughtExceptionHandler uncaughtException
GRAVE: An exception was thrown:
java.lang.IllegalStateException: Bug in FXOMRefresher: FXML dumped in /var/folders/ky/7_fc88ls2q97_f16j48nyrt0000jvp/T/DTL-5996-8810260458226565524.fxml
at com.oracle.javafx.scenebuilder.kit.fxom.FXOMRefresher.refresh(FXOMRefresher.java:84)
at com.oracle.javafx.scenebuilder.kit.fxom.FXOMDocument.refreshSceneGraph(FXOMDocument.java:275)
at com.oracle.javafx.scenebuilder.kit.fxom.FXOMDocument.endUpdate(FXOMDocument.java:262)
at com.oracle.javafx.scenebuilder.kit.fxom.FXOMNodes.newDocument(FXOMNodes.java:279)
at com.oracle.javafx.scenebuilder.kit.fxom.FXOMArchive.<init>(FXOMArchive.java:56)
at com.oracle.javafx.scenebuilder.kit.metadata.util.ClipboardEncoder.makeEncoding(ClipboardEncoder.java:78)
at com.oracle.javafx.scenebuilder.kit.editor.EditorController.performCopy(EditorController.java:1678)
at com.oracle.javafx.scenebuilder.kit.editor.EditorController.performControlAction(EditorController.java:1332)
at com.oracle.javafx.scenebuilder.app.DocumentWindowController.performCopy(DocumentWindowController.java:1398)
at com.oracle.javafx.scenebuilder.app.DocumentWindowController.performControlAction(DocumentWindowController.java:586)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$DocumentControlActionController.perform(MenuBarController.java:1637)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.handleOnActionMenu(MenuBarController.java:1115)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.access$800(MenuBarController.java:90)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$20.handle(MenuBarController.java:1108)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$20.handle(MenuBarController.java:1104)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:204)
at javafx.scene.control.MenuItem.fire(MenuItem.java:462)
at com.sun.javafx.scene.control.GlobalMenuAdapter$5.handle(GlobalMenuAdapter.java:158)
at com.sun.javafx.scene.control.GlobalMenuAdapter$5.handle(GlobalMenuAdapter.java:156)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:204)
at javafx.scene.control.MenuItem.fire(MenuItem.java:462)
at com.sun.javafx.tk.quantum.GlassSystemMenu$6.action(GlassSystemMenu.java:234)
Caused by: java.io.IOException: javafx.fxml.LoadException: Value "f1" does not exist.
/Users/elp/Desktop/HG/R21/scenebuilder/SceneBuilderKit/test/com/oracle/javafx/scenebuilder/kit/fxom/FXOMClonerTest.fxml:9

at com.oracle.javafx.scenebuilder.kit.fxom.FXOMLoader.load(FXOMLoader.java:92)
at com.oracle.javafx.scenebuilder.kit.fxom.FXOMDocument.<init>(FXOMDocument.java:80)
at com.oracle.javafx.scenebuilder.kit.fxom.FXOMRefresher.refresh(FXOMRefresher.java:60)
... 35 more
Caused by: javafx.fxml.LoadException: Value "f1" does not exist.
/Users/elp/Desktop/HG/R21/scenebuilder/SceneBuilderKit/test/com/oracle/javafx/scenebuilder/kit/fxom/FXOMClonerTest.fxml:9

at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2613)
at javafx.fxml.FXMLLoader.access$100(FXMLLoader.java:104)
at javafx.fxml.FXMLLoader$ReferenceElement.constructValue(FXMLLoader.java:1200)
at javafx.fxml.FXMLLoader$ValueElement.processStartElement(FXMLLoader.java:740)
at javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2723)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2527)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2425)
at com.oracle.javafx.scenebuilder.kit.fxom.FXOMLoader.load(FXOMLoader.java:89)
... 37 more