The following line of code:

        region.setStyle(" -fx-background-color: black;");

causes an NPE:

WARNING: com.sun.javafx.css.parser.CSSParser declaration Expected IDENT at file:/D:/JavaFX/repos/jfx/apps/internal/BugsFiling/build/classes/[1,2]
Exception in Application start method
Exception in thread "main" java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:203)
at com.sun.javafx.application.LauncherImpl.access$000(LauncherImpl.java:18)
at com.sun.javafx.application.LauncherImpl$1.run(LauncherImpl.java:56)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
at com.sun.javafx.css.StyleManager$Cache.getStyles(StyleManager.java:867)
at com.sun.javafx.css.StyleManager$Cache.lookup(StyleManager.java:824)
at com.sun.javafx.css.StyleManager$Cache.access$1700(StyleManager.java:766)
at com.sun.javafx.css.StyleManager$StylesheetContainer.getStyleHelper(StyleManager.java:661)
at com.sun.javafx.css.StyleManager$StylesheetContainer.access$1200(StyleManager.java:523)
at com.sun.javafx.css.StyleManager.getStyleHelper(StyleManager.java:450)
at javafx.scene.Node.impl_createStyleHelper(Node.java:5466)
at javafx.scene.Node.impl_processCSS(Node.java:5454)
at javafx.scene.Parent.impl_processCSS(Parent.java:847)
at javafx.stage.Window.impl_visibleChanging(Window.java:581)
at javafx.stage.Stage.impl_visibleChanging(Stage.java:502)
at javafx.stage.Window$13.invalidated(Window.java:489)
at javafx.beans.property.BooleanPropertyBase.markInvalid(BooleanPropertyBase.java:76)
at javafx.beans.property.BooleanPropertyBase.set(BooleanPropertyBase.java:110)
at javafx.stage.Window.setVisible(Window.java:561)
at javafx.stage.Stage.setVisible(Stage.java:109)
at SpaceInStyleBug.start(SpaceInStyleBug.java:28)
at com.sun.javafx.application.LauncherImpl$4.run(LauncherImpl.java:164)
at com.sun.javafx.application.PlatformImpl$4.run(PlatformImpl.java:126)
at com.sun.javafx.application.PlatformImpl$3.run(PlatformImpl.java:102)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:29)
at com.sun.glass.ui.win.WinApplication$1$1.run(WinApplication.java:49)
... 1 more