1. Launch hello.HelloDialogs
2. Enter some text
3. press "Enter" (Carriage return)
4. Crash, Call stack attached.

Used javafx build "329" (Sanity testing, non-jigsaw mode)

Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
j com.sun.glass.ui.win.WinApplication._enterNestedEventLoopImpl()Ljava/lang/Object;+0 javafx.graphics@9-ea
j com.sun.glass.ui.win.WinApplication._enterNestedEventLoop()Ljava/lang/Object;+15 javafx.graphics@9-ea
j com.sun.glass.ui.Application.enterNestedEventLoop()Ljava/lang/Object;+14 javafx.graphics@9-ea
j com.sun.glass.ui.EventLoop.enter()Ljava/lang/Object;+42 javafx.graphics@9-ea
j com.sun.javafx.tk.quantum.QuantumToolkit.enterNestedEventLoop(Ljava/lang/Object;)Ljava/lang/Object;+107 javafx.graphics@9-ea
j javafx.stage.Stage.showAndWait()V+93 javafx.graphics@9-ea
j javafx.scene.control.HeavyweightDialog.showAndWait()V+22 javafx.controls@9-ea
j javafx.scene.control.Dialog.showAndWait()Ljava/util/Optional;+86 javafx.controls@9-ea
j hello.HelloDialogs.showDialog(Ljavafx/scene/control/Dialog;)V+37
j hello.HelloDialogs.lambda$start$4(Ljavafx/event/ActionEvent;)V+39
j hello.HelloDialogs$$Lambda$92.handle(Ljavafx/event/Event;)V+8