Generating content for ArrayController. Returns: Uncaught TypeError: Object function () { return App.Article.createRecord({title: "my article"}); } has no method 'addArrayObserver'

controller.js

App.IndexController = Ember.ArrayController.extend({
  software_index: function() {
    // this will use .find() later
    return Ember.A([App.Text.find()]);
  }.property()
});

App.PostsIndexController = Ember.ArrayController.extend();

index.hbs

<div class="content">
  <h1>Software</h1>
  {{render "posts/index" software_index}}
</div>

posts_index.hbs

{{#each controller}}
  <h2><a href="#">{{title}}</a></h2>
{{/each}}