<linearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#FFCCCCCC" android:orientation="vertical" tools:context=".MainDrawingActivity" > </linearLayout> I can't figure out what's missing... help please?