title: Being told project is not using the gradle build system when it is
body: <p>When I open my project in Android Studio, I always get this.
  <img src="https://i.stack.imgur.com/EwOhG.png" alt="Error when project is opened"></p>
  
  <p>Back when Android Studio first came out, I went through <a href="http://developer.android.com/sdk/installing/migrate.html" rel="noreferrer">this</a> process so the project should have the Gradle build system. There is a build.gradle file in the root of the project. 
  I can still build and run the project, but I don't understand why it always says this since the project should use gradle build system. Any help with this would be great.</p>