deferReadiness.js

//This code gives this error: 
// Uncaught Error: assertion failed: Ember.Object.create no longer supports defining methods that call _super. 

var App = Ember.Application.create({
    init:function(){
      this._super.deferReadiness();
    }
  });

It should be like:

init: function() {
  this.deferReadiness();
  this._super();
}

Also see: emberjs/ember.js#2184