Open SB. Add HTML editor to content panel. See console output

SEVERE: javafx.scene.control.Control loadSkinClass Failed to load skin 'StringProperty [bean: PopupButton[id=null, styleClass=menu-button popup-button], name: skinClassName, value: com.sun.javafx.scene.control.skin.MenuButtonSkin]' for control PopupButton[id=null, styleClass=menu-button popup-button]
java.lang.IllegalArgumentException: java.lang.ClassCastException@1763e19
at sun.reflect.GeneratedConstructorAccessor11.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at javafx.scene.control.Control.loadSkinClass(Control.java:999)
at javafx.scene.control.Control.access$500(Control.java:74)
at javafx.scene.control.Control$12.invalidated(Control.java:918)
at javafx.beans.property.StringPropertyBase.markInvalid(StringPropertyBase.java:127)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:161)
at com.sun.javafx.css.StyleableStringProperty.set(StyleableStringProperty.java:71)
at javafx.scene.control.Control$12.set(Control.java:910)
at com.sun.javafx.css.StyleableStringProperty.applyStyle(StyleableStringProperty.java:59)
at com.sun.javafx.css.StyleableStringProperty.applyStyle(StyleableStringProperty.java:31)
at com.sun.javafx.css.StyleableProperty.set(StyleableProperty.java:62)
at com.sun.javafx.css.StyleHelper.transitionToState(StyleHelper.java:798)
at javafx.scene.Node.impl_processCSS(Node.java:6469)
at javafx.scene.Parent.impl_processCSS(Parent.java:1127)
at javafx.scene.control.Control.impl_processCSS(Control.java:1109)
at javafx.scene.Parent.impl_processCSS(Parent.java:1134)
at javafx.scene.Parent.impl_processCSS(Parent.java:1134)
at javafx.scene.Parent.impl_processCSS(Parent.java:1134)
at javafx.scene.control.Control.impl_processCSS(Control.java:1109)
at javafx.scene.Parent.impl_processCSS(Parent.java:1134)
at javafx.scene.Parent.impl_processCSS(Parent.java:1134)
at javafx.scene.Parent.impl_processCSS(Parent.java:1134)
at javafx.scene.control.Control.impl_processCSS(Control.java:1109)
at com.oracle.javafx.authoring.Deprecation.processCSS(Deprecation.java:85)
at com.oracle.javafx.authoring.css.CssUtils.doApplyCss(CssUtils.java:836)
at com.oracle.javafx.authoring.css.CssUtils.access$200(CssUtils.java:52)
at com.oracle.javafx.authoring.css.CssUtils$1.run(CssUtils.java:819)
at com.sun.javafx.application.PlatformImpl$3.run(PlatformImpl.java:141)
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$2$1.run(WinApplication.java:62)
at java.lang.Thread.run(Thread.java:662)