sorry to ask also a stupid question - I cannot make the demo work either:
The demo can be compiled but when I click on any button, it crashes:
Program started.
java.lang.RuntimeException: java.lang.NoSuchMethodError: com.sun.javafx.css.StyleManager.getPseudoclassMask(Ljava/lang/String

J
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:114)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:82)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:84)
at anywheresoftware.b4j.objects.NodeWrapper$1.handle(NodeWrapper.java:64)
at anywheresoftware.b4j.objects.NodeWrapper$1.handle(NodeWrapper.java:1)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$ClickGenerator.postProcess(Scene.java:3437)
at javafx.scene.Scene$ClickGenerator.access$7900(Scene.java:3365)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3733)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3452)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1728)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2461)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:348)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:273)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:382)
at com.sun.glass.ui.View.handleMouseEvent(View.java:553)
at com.sun.glass.ui.View.notifyMouse(View.java:925)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$141(WinApplication.java:102)
at com.sun.glass.ui.win.WinApplication$$Lambda$38/2075313.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoSuchMethodError: com.sun.javafx.css.StyleManager.getPseudoclassMask(Ljava/lang/String

J
at anywheresoftware.b4a.giuseppe.salvi.dialogs.DialogWrapper$FXDialog$RootPane.<clinit>(DialogWrapper.java:1381)
at anywheresoftware.b4a.giuseppe.salvi.dialogs.DialogWrapper$FXDialog.<init>(DialogWrapper.java:1201)
at anywheresoftware.b4a.giuseppe.salvi.dialogs.DialogWrapper$FXDialog.<init>(DialogWrapper.java:1157)
at anywheresoftware.b4a.giuseppe.salvi.dialogs.DialogWrapper$DialogTemplate.<init>(DialogWrapper.java:682)
at anywheresoftware.b4a.giuseppe.salvi.dialogs.DialogWrapper.showSimpleContentDialog(DialogWrapper.java:556)
at anywheresoftware.b4a.giuseppe.salvi.dialogs.DialogWrapper.showWarningDialog(DialogWrapper.java:333)
at anywheresoftware.b4a.giuseppe.salvi.dialogs.DialogWrapper.showWarningDialog(DialogWrapper.java:323)
at anywheresoftware.b4a.giuseppe.salvi.dialogs.BetterDialogsWrapper.ShowWarning(BetterDialogsWrapper.java:147)
at b4j.example.main._warning_mouseclicked(main.java:230)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:563)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:221)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:156)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
... 33 more
Maybe someone has a good idea what's going on here,
Thanks a lot,
Chris