Xamarin.Forms.1.5.1 Released issues

Hello,
After upgrade xamarin forms 1.5.1 version getting following issues :

• Getting error to create splash screen. In earlier version following theme working good.

But now  null reference exception occurs.

After set parent = Theme.AppCompat then also problem not resolved.

• Another issue is unable to create "values-21" folder in resource directory. Shows following error msg :
  Invalid resource directory name: "res values-21".

  Thank you