title: Shape and background error in Android Studio
body: <p>I'm pretty new in Android world and I've encountered a problem. I'm trying to do this pice of code in my first exercise <a href="http://developer.android.com/guide/topics/resources/drawable-resource.html#Shape" rel="nofollow noreferrer">http://developer.android.com/guide/topics/resources/drawable-resource.html#Shape</a> and I have errors without errors. I mean I have red exclamaition mark, but no error message occured. 
  And I have no clue, what I am doing wrong. Any ideas? Will be greatful for any help :)
  <img src="https://i.stack.imgur.com/id6Rg.jpg" alt="i.stack.imgur.com/id6Rg.jpg"></p>