title: Has no method 'addArrayObserver' during {{#linkTo}} click
body: <p>Hey not sure if anyone can help me, but I have been struggling with this error for a long time:</p>
  
  <p><code>"Uncaught TypeError: Object &lt;App.AssetType:ember408:2&gt; has no method 'addArrayObserver'"</code></p>
  
  <p>Here is the template with the <code>{{#linkTo}}</code>'s that produce this error when clicked</p>
  
  <pre><code>&lt;div class="row"&gt;
    &lt;div class="twelve columns"&gt;
      &lt;h2&gt;{{title}} - Assets&lt;/h2&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="row"&gt;
    &lt;div class="three columns"&gt;
      &lt;ul&gt;
        {{#each assetTypes}}
        {{#linkTo 'product.filter' this}}{{title}}{{/linkTo}}
        {{/each}}
      &lt;/ul&gt;
    &lt;/div&gt;
    &lt;div class="nine columns"&gt;
      {{outlet}}
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>and the Application code</p>
  
  <pre><code>window.App = Ember.Application.create
    rootElement: '.solution_products_documents'
  
  App.ApplicationRoute = Ember.Route.extend
    model: -&gt;
      App.Product.find()
  App.ApplicationController = Ember.ArrayController.extend
    sortProperties: ['title']
  
  App.ProductRoute = Ember.Route.extend
    model: (params) -&gt;
      App.Product.find params.product_id
    setupController: (controller, model) -&gt;
      controller.set 'documents', model.get 'document_ids'
  
  App.ProductController = Ember.ObjectController.extend
    assetTypes: (-&gt;
      docs = @get('documents')
      docs.getEach 'asset_type_id'
    ).property('documents')
  
  App.ProductFilterRoute = Ember.Route.extend
    model: (params) -&gt;
      type = App.AssetType.find params.asset_type_id
      product = this.modelFor 'product'
      docs = product.get 'document_ids'
      model = docs.filterProperty 'asset_type_id', type
  App.ProductFilterController = Ember.ArrayController.extend()
  
  App.Router.map -&gt;
    @route 'index', { path: '/' }
    @resource 'product', { path: '/products/:product_id' }, -&gt;
      @route 'filter', { path: '/filter-by/:asset_type_id' }
  
  ##
  # MODELS / EMBER-DATA
  ##
  
  serializer = DS.JSONSerializer.create()
  
  serializer.configure 'App.Document',
    sideloadAs: 'documents'
  
  serializer.configure 'App.AssetType',
    sideloadAs: 'asset_types'
  
  serializer.configure 'App.Product',
    sideloadAs: 'products'
  
  App.RestAdaptor = DS.RESTAdapter.extend
    serializer: serializer
    namespace: URL.slice 1
  DS.Store.extend(
    adapter: App.RestAdaptor
    revision: 11
  ).create()
  
  App.Product = DS.Model.extend
    title: DS.attr 'string'
    document_ids: DS.hasMany 'App.Document'
  
  App.Document = DS.Model.extend
    title: DS.attr 'string'
    product_id: DS.belongsTo 'App.Product'
    asset_type_id: DS.belongsTo 'App.AssetType'
  
  App.AssetType = DS.Model.extend
    title: DS.attr 'string'
    document_ids: DS.hasMany 'App.Document'
  
  ######### /&gt; END MODELS #################
  </code></pre>
  
  <p>Everything works as planned if I put the URL <code>#/products/4/filter-by/2</code> into the address bar. It's only when I click the <code>{{#linkTo}}</code>'s that I get this error and the content is not displayed. The error is thrown before it get's to the <code>App.ProductFilterRoute</code> because the <code>debugger</code> statement in the route is not executed, but it is on page refresh.</p>
  
  <p>Any help or direction is greatly appreciated, as I don't really know where to look.</p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>If I do not use the <code>{{#linkTo}}</code> helper and instead manually construct the url </p>
  
  <p><code>&lt;a href="#/products/{{unbound controller.content.id}}/filter-by/{{unbound this.id}}"&gt;{{title}}&lt;/a&gt;</code></p>
  
  <p>everything works fine. What is different between the linkTo and manual href?</p>