Using the CSS Analyzer in SB 2, I get the following exception when a Button with its textFill property impacted by all the StyleOrigin (USER, AUTHOR, INLINE) is selected.
I don't have a test case for now, will try to make one.

java.lang.NullPointerException
at javafx.scene.control.Labeled$8.applyStyle(Labeled.java:464)
at javafx.scene.control.Labeled$8.applyStyle(Labeled.java:441)
at javafx.scene.CssStyleHelper.transitionToState(CssStyleHelper.java:798)
at javafx.scene.Node.impl_processCSS(Node.java:8881)
at javafx.scene.Parent.impl_processCSS(Parent.java:1237)
at javafx.scene.control.Control.impl_processCSS(Control.java:867)
at javafx.scene.Parent.impl_processCSS(Parent.java:1268)
at javafx.scene.Parent.impl_processCSS(Parent.java:1268)
at javafx.scene.Parent.impl_processCSS(Parent.java:1268)
at javafx.scene.Parent.impl_processCSS(Parent.java:1268)
at javafx.scene.Node.processCSS(Node.java:8720)
at javafx.scene.Node.processCSS(Node.java:8713)
at javafx.scene.Scene.doCSSPass(Scene.java:557)
at javafx.scene.Scene.access$3500(Scene.java:193)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2340)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:329)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:479)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:460)
at com.sun.javafx.tk.quantum.QuantumToolkit$13.run(QuantumToolkit.java:327)
at com.sun.glass.ui.InvokeLaterDispatcher$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$4$1.run(WinApplication.java:112)
at java.lang.Thread.run(Thread.java:744)