I'm seeing this when I click focus to or from a TextArea with null text:

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
        at java.text.StringCharacterIterator.<init>(Unknown Source)
        at java.text.StringCharacterIterator.<init>(Unknown Source)
        at java.text.BreakIterator.setText(Unknown Source)
        at com.sun.javafx.scene.control.skin.Utils.getHitInsertionIndex(Unknown Source)
        at com.sun.javafx.scene.control.behavior.TextAreaBehavior.mousePressed(Unknown Source)
        at com.sun.javafx.scene.control.skin.TextAreaSkin$ContentView$1.handle(Unknown Source)
        at com.sun.javafx.scene.control.skin.TextAreaSkin$ContentView$1.handle(Unknown Source)
        at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)
        at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
        at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
        at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
        at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
        at javafx.event.Event.fireEvent(Unknown Source)
        at javafx.scene.Scene$MouseHandler.process(Unknown Source)
        at javafx.scene.Scene$MouseHandler.access$1800(Unknown Source)
        at javafx.scene.Scene.impl_processMouseEvent(Unknown Source)
        at javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
        at com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
        at com.sun.glass.ui.View.notifyMouse(Unknown Source)
        at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
        at com.sun.glass.ui.win.WinApplication.access$300(Unknown Source)
        at com.sun.glass.ui.win.WinApplication$4$1.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)