android - Theme Editor does not show the actual controls being affected by theme -

i'm having problem theme editor where, instead of showing checkbox in checkbox preview, literally displays word "checkbox". occurs in app bar, progressbar (indeterminate , horizontal), seekbar, , radiobutton previews.

<resources>  <!-- base application theme. --> <style name="apptheme" parent="theme.appcompat.light.darkactionbar">     <!-- customize theme here. -->     <item name="colorprimary">@color/colorprimary</item>     <item name="colorprimarydark">@color/colorprimarydark</item>     <item name="coloraccent">@color/specialred</item>     <item name="android:textcolorprimary">@color/primarytext</item>     <item name="android:textcolorsecondary">@color/secondarytext</item> </style>  </resources>