title: Android Studio: cannot find "Hello World apps" on emulator screen
body: <p>I'm new in android development, especially android studio, i try "Hello Word" for my first app, but not found "Hello World app" in my emulator screen. it's look like this:</p>
  
  <p><img src="https://i.stack.imgur.com/mNhYe.jpg" alt="screen shoot for emulator"></p>
  
  <p>I search these error, but only event log say: <code>Session 'app': error</code>. Still didn't get any solution even after a lot of searching. Need help please, for my learning. </p>