Preview: Failed to load AppCompat ActionBar with unknown error


#1

From Page 610 Listing 32.3 onwards when I try to see the preview of fragment_sunset.xml I got the message:“Render problem Failed to load AppCompat ActionBar with unknown error.” and the preview shows nothing I get the solution by changing style.xml App Theme to
"<style name=“AppTheme"parent=“Base.Theme.AppCompat.Light.DarkActionBar”>”
Anybody can explain to me why do I have to make such change?