3DViewer gets fatal exception in FXMLLoader on startup

Error resolving onAction='#open', either the event handler is not in the Namespace or there is an error in the script.
file:/C:/Users/kcr/javafx/8-kcr-gfx/jfx/artifacts/apps/ga-samples/3DViewer.jar!/com/javafx/experiments/jfx3dviewer/main.fxml:53
  at javafx.fxml.FXMLLoader$Element.processEventHandlerAttributes(FXMLLoader.java:589)
  at javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:750)
  at javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2688)
  at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2389)
  at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2283)
  at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3068)
  at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3046)
  at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3031)
  at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3018)
  at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3007)
  at com.javafx.experiments.jfx3dviewer.Jfx3dViewerApp.start(Jfx3dViewerApp.java:67)
  at com.sun.javafx.application.LauncherImpl$5.run(LauncherImpl.java:811)
  at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:331)
  at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:297)
  at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:294)
  at java.security.AccessController.doPrivileged(Native Method)
  at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:294)
  at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
  at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
  at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
  at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:101)
  at java.lang.Thread.run(Thread.java:724)

Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:351)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:304)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:491)
at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:778)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:868)
at com.sun.javafx.application.LauncherImpl.access$000(LauncherImpl.java:55)
at com.sun.javafx.application.LauncherImpl$1.run(LauncherImpl.java:157)
at java.lang.Thread.run(Thread.java:724)
Caused by: javafx.fxml.LoadException: Error resolving onAction='#open', either the event handler is not in the Namespace or there is an error in the script.
at javafx.fxml.FXMLLoader$Element.processEventHandlerAttributes(FXMLLoader.java:589)
at javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:750)
at javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2688)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2389)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2283)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3068)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3046)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3031)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3018)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3007)
at com.javafx.experiments.jfx3dviewer.Jfx3dViewerApp.start(Jfx3dViewerApp.java:67)
at com.sun.javafx.application.LauncherImpl$5.run(LauncherImpl.java:811)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:331)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:297)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:294)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:101)
... 1 more
Exception running application com.javafx.experiments.jfx3dviewer.Jfx3dViewerApp