diff --git a/app/assets/javascripts/discourse/components/visible.js.es6 b/app/assets/javascripts/discourse/components/visible.js.es6
index 1c3532c2081..f9570e412ea 100644
--- a/app/assets/javascripts/discourse/components/visible.js.es6
+++ b/app/assets/javascripts/discourse/components/visible.js.es6
@@ -4,7 +4,7 @@ export default Ember.Component.extend({
   }.observes("visible"),
 
   render: function(buffer){
-    if (this._state !== 'inDOM' && this._state !== 'preRender') { return; }
+    if (this._state !== 'inDOM' && this._state !== 'preRender' && this._state !== 'inBuffer') { return; }
     if (!this.get("visible")) { return; }
 
     return this._super(buffer);
diff --git a/app/assets/javascripts/discourse/controllers/flag-action-type.js.es6 b/app/assets/javascripts/discourse/controllers/flag-action-type.js.es6
index 484fd12f66e..7ff592a4c19 100644
--- a/app/assets/javascripts/discourse/controllers/flag-action-type.js.es6
+++ b/app/assets/javascripts/discourse/controllers/flag-action-type.js.es6
@@ -7,22 +7,22 @@ export default ObjectController.extend({
   message: Em.computed.alias('controllers.flag.message'),
 
   customPlaceholder: function(){
-    return I18n.t("flagging.custom_placeholder_" + this.get('name_key'));
-  }.property('name_key'),
+    return I18n.t("flagging.custom_placeholder_" + this.get('model.name_key'));
+  }.property('model.name_key'),
 
   formattedName: function(){
-    if (this.get("is_custom_flag")) {
-      return this.get('name').replace("{{username}}", this.get('controllers.flag.username'));
+    if (this.get("model.is_custom_flag")) {
+      return this.get('model.name').replace("{{username}}", this.get('controllers.flag.model.username'));
     } else {
-      return I18n.t("flagging.formatted_name." + this.get('name_key'));
+      return I18n.t("flagging.formatted_name." + this.get('model.name_key'));
     }
-  }.property('name', 'name_key', 'is_custom_flag'),
+  }.property('model.name', 'model.name_key', 'model.is_custom_flag'),
 
   selected: function() {
     return this.get('model') === this.get('controllers.flag.selected');
   }.property('controllers.flag.selected'),
 
-  showMessageInput: Em.computed.and('is_custom_flag', 'selected'),
+  showMessageInput: Em.computed.and('model.is_custom_flag', 'selected'),
   showDescription: Em.computed.not('showMessageInput'),
 
   customMessageLengthClasses: function() {
diff --git a/app/assets/javascripts/discourse/controllers/flag.js.es6 b/app/assets/javascripts/discourse/controllers/flag.js.es6
index 0a24d0d280a..4708d2e9505 100644
--- a/app/assets/javascripts/discourse/controllers/flag.js.es6
+++ b/app/assets/javascripts/discourse/controllers/flag.js.es6
@@ -2,8 +2,13 @@ import ModalFunctionality from 'discourse/mixins/modal-functionality';
 import ObjectController from 'discourse/controllers/object';
 
 export default ObjectController.extend(ModalFunctionality, {
+  userDetails: null,
+  selected: null,
+  flagTopic: null,
+  message: null,
+  topicActionByName: null,
 
-  onShow: function() {
+  onShow() {
     this.set('selected', null);
   },
 
@@ -11,32 +16,31 @@ export default ObjectController.extend(ModalFunctionality, {
     if (!this.get('flagTopic')) {
       return this.get('model.flagsAvailable');
     } else {
-      var self = this,
+      const self = this,
           lookup = Em.Object.create();
 
-      _.each(this.get("actions_summary"),function(a) {
-        var actionSummary;
+      _.each(this.get("model.actions_summary"),function(a) {
         a.flagTopic = self.get('model');
         a.actionType = self.site.topicFlagTypeById(a.id);
-        actionSummary = Discourse.ActionSummary.create(a);
+        const actionSummary = Discourse.ActionSummary.create(a);
         lookup.set(a.actionType.get('name_key'), actionSummary);
       });
       this.set('topicActionByName', lookup);
 
       return this.site.get('topic_flag_types').filter(function(item) {
-        return _.any(self.get("actions_summary"), function(a) {
+        return _.any(self.get("model.actions_summary"), function(a) {
           return (a.id === item.get('id') && a.can_act);
         });
       });
     }
-  }.property('post', 'flagTopic', 'actions_summary.@each.can_act'),
+  }.property('post', 'flagTopic', 'model.actions_summary.@each.can_act'),
 
   submitEnabled: function() {
-    var selected = this.get('selected');
+    const selected = this.get('selected');
     if (!selected) return false;
 
     if (selected.get('is_custom_flag')) {
-      var len = this.get('message.length') || 0;
+      const len = this.get('message.length') || 0;
       return len >= Discourse.SiteSettings.min_private_message_post_length &&
              len <= Discourse.PostActionType.MAX_MESSAGE_LENGTH;
     }
@@ -63,22 +67,21 @@ export default ObjectController.extend(ModalFunctionality, {
   }.property('selected.is_custom_flag'),
 
   actions: {
-    takeAction: function() {
+    takeAction() {
       this.send('createFlag', {takeAction: true});
-      this.set('hidden', true);
+      this.set('model.hidden', true);
     },
 
-    createFlag: function(opts) {
-      var self = this;
-      var postAction; // an instance of ActionSummary
+    createFlag(opts) {
+      const self = this;
+      let postAction; // an instance of ActionSummary
       if (!this.get('flagTopic')) {
-        postAction = this.get('actionByName.' + this.get('selected.name_key'));
+        postAction = this.get('model.actionByName.' + this.get('selected.name_key'));
       } else {
         postAction = this.get('topicActionByName.' + this.get('selected.name_key'));
       }
-      var params = this.get('selected.is_custom_flag') ? {message: this.get('message')} : {};
-
-      if (opts) params = $.extend(params, opts);
+      let params = this.get('selected.is_custom_flag') ? {message: this.get('message')} : {};
+      if (opts) { params = $.extend(params, opts); }
 
       this.send('hideModal');
 
@@ -97,7 +100,7 @@ export default ObjectController.extend(ModalFunctionality, {
       });
     },
 
-    changePostActionType: function(action) {
+    changePostActionType(action) {
       this.set('selected', action);
     },
   },
@@ -115,12 +118,12 @@ export default ObjectController.extend(ModalFunctionality, {
   usernameChanged: function() {
     this.set('userDetails', null);
     this.fetchUserDetails();
-  }.observes('username'),
+  }.observes('model.username'),
 
   fetchUserDetails: function() {
-    if( Discourse.User.currentProp('staff') && this.get('username') ) {
-      var flagController = this;
-      Discourse.AdminUser.find(this.get('username').toLowerCase()).then(function(user){
+    if( Discourse.User.currentProp('staff') && this.get('model.username') ) {
+      const flagController = this;
+      Discourse.AdminUser.find(this.get('model.username').toLowerCase()).then(function(user){
         flagController.set('userDetails', user);
       });
     }
diff --git a/app/assets/javascripts/discourse/controllers/quote-button.js.es6 b/app/assets/javascripts/discourse/controllers/quote-button.js.es6
index c73822188c0..0a4c0e3ada6 100644
--- a/app/assets/javascripts/discourse/controllers/quote-button.js.es6
+++ b/app/assets/javascripts/discourse/controllers/quote-button.js.es6
@@ -43,7 +43,7 @@ export default DiscourseController.extend({
     if (this.get('buffer') === selectedText) return;
 
     // we need to retrieve the post data from the posts collection in the topic controller
-    const postStream = this.get('controllers.topic.postStream');
+    const postStream = this.get('controllers.topic.model.postStream');
     this.set('post', postStream.findLoadedPost(postId));
     this.set('buffer', selectedText);
 
diff --git a/app/assets/javascripts/discourse/controllers/share.js.es6 b/app/assets/javascripts/discourse/controllers/share.js.es6
index abf8cd081dd..2e662dc217a 100644
--- a/app/assets/javascripts/discourse/controllers/share.js.es6
+++ b/app/assets/javascripts/discourse/controllers/share.js.es6
@@ -2,7 +2,7 @@ import Sharing from 'discourse/lib/sharing';
 
 export default Ember.Controller.extend({
   needs: ['topic'],
-  title: Ember.computed.alias('controllers.topic.title'),
+  title: Ember.computed.alias('controllers.topic.model.title'),
 
   displayDate: function() {
     return Discourse.Formatter.longDateNoYear(new Date(this.get('date')));
diff --git a/app/assets/javascripts/discourse/controllers/topic.js.es6 b/app/assets/javascripts/discourse/controllers/topic.js.es6
index 245b5d99730..321d2740ad0 100644
--- a/app/assets/javascripts/discourse/controllers/topic.js.es6
+++ b/app/assets/javascripts/discourse/controllers/topic.js.es6
@@ -536,7 +536,7 @@ export default ObjectController.extend(Discourse.SelectedPostsCount, BufferedCon
     return canDelete;
   }.property('selectedPostsCount'),
 
-  hasError: Ember.computed.or('notFoundHtml', 'message'),
+  hasError: Ember.computed.or('model.notFoundHtml', 'model.message'),
   noErrorYet: Ember.computed.not('hasError'),
 
   multiSelectChanged: function() {
@@ -567,8 +567,8 @@ export default ObjectController.extend(Discourse.SelectedPostsCount, BufferedCon
   },
 
   showStarButton: function() {
-    return Discourse.User.current() && !this.get('isPrivateMessage');
-  }.property('isPrivateMessage'),
+    return Discourse.User.current() && !this.get('model.isPrivateMessage');
+  }.property('model.isPrivateMessage'),
 
   loadingHTML: function() {
     return spinnerHTML;
@@ -666,7 +666,7 @@ export default ObjectController.extend(Discourse.SelectedPostsCount, BufferedCon
   readPosts(topicId, postNumbers) {
     const postStream = this.get('model.postStream');
 
-    if(this.get('model.postStream.topic.id') === topicId){
+    if (postStream.get('topic.id') === topicId){
       _.each(postStream.get('posts'), function(post){
         // optimise heavy loop
         // TODO identity map for postNumber
@@ -687,7 +687,7 @@ export default ObjectController.extend(Discourse.SelectedPostsCount, BufferedCon
     if (!post) { return; }
 
     const postStream = this.get('model.postStream'),
-        firstLoadedPost = postStream.get('firstLoadedPost');
+          firstLoadedPost = postStream.get('firstLoadedPost');
 
     this.set('model.currentPost', post.get('post_number'));
 
diff --git a/app/assets/javascripts/discourse/controllers/user-card.js.es6 b/app/assets/javascripts/discourse/controllers/user-card.js.es6
index 8534bfdd3b8..2786d25f779 100644
--- a/app/assets/javascripts/discourse/controllers/user-card.js.es6
+++ b/app/assets/javascripts/discourse/controllers/user-card.js.es6
@@ -90,7 +90,7 @@ export default Ember.Controller.extend({
 
   actions: {
     togglePosts(user) {
-      const postStream = this.get('controllers.topic.postStream');
+      const postStream = this.get('postStream');
       postStream.toggleParticipant(user.get('username'));
       this.close();
     },
diff --git a/app/assets/javascripts/discourse/models/post-stream.js.es6 b/app/assets/javascripts/discourse/models/post-stream.js.es6
index 532cc6a991b..c96a4f9e31e 100644
--- a/app/assets/javascripts/discourse/models/post-stream.js.es6
+++ b/app/assets/javascripts/discourse/models/post-stream.js.es6
@@ -707,7 +707,7 @@ const PostStream = RestModel.extend({
     const status = result.status;
 
     const topic = this.get('topic');
-    topic.set('loadingFilter', false);
+    this.set('loadingFilter', false);
     topic.set('errorLoading', true);
 
     // If the result was 404 the post is not found
diff --git a/app/assets/javascripts/discourse/models/topic.js.es6 b/app/assets/javascripts/discourse/models/topic.js.es6
index abd3ef443f2..9823080304b 100644
--- a/app/assets/javascripts/discourse/models/topic.js.es6
+++ b/app/assets/javascripts/discourse/models/topic.js.es6
@@ -1,6 +1,9 @@
 import RestModel from 'discourse/models/rest';
 
 const Topic = RestModel.extend({
+  message: null,
+  errorTitle: null,
+  errorLoading: false,
 
   // returns createdAt if there's no bumped date
   bumpedAt: function() {
diff --git a/app/assets/javascripts/discourse/templates/modal/flag.hbs b/app/assets/javascripts/discourse/templates/modal/flag.hbs
index 154c1926692..d7a6cc872b7 100644
--- a/app/assets/javascripts/discourse/templates/modal/flag.hbs
+++ b/app/assets/javascripts/discourse/templates/modal/flag.hbs
@@ -4,9 +4,9 @@
     {{#each f in flagsAvailable itemController="flag-action-type"}}
       <div class='controls'>
         <label class='radio'>
-          <input type='radio' id="radio_{{unbound f.name_key}}" {{action "changePostActionType" f}} name='post_action_type_index'> <strong>{{f.formattedName}}</strong>
+          <input type='radio' id="radio_{{unbound f.model.name_key}}" {{action "changePostActionType" f}} name='post_action_type_index'> <strong>{{f.formattedName}}</strong>
           {{#if f.showDescription}}
-            <div class='description'>{{{f.description}}}</div>
+            <div class='description'>{{{f.model.description}}}</div>
           {{/if}}
         </label>
         {{#if f.showMessageInput}}
diff --git a/app/assets/javascripts/discourse/templates/topic.hbs b/app/assets/javascripts/discourse/templates/topic.hbs
index 5bf5be51ae7..113ec187afa 100644
--- a/app/assets/javascripts/discourse/templates/topic.hbs
+++ b/app/assets/javascripts/discourse/templates/topic.hbs
@@ -124,8 +124,8 @@
 {{else}}
   <div class='container'>
     {{#conditional-loading-spinner condition=noErrorYet}}
-      {{#if notFoundHtml}}
-        {{{notFoundHtml}}}
+      {{#if model.notFoundHtml}}
+        {{{model.notFoundHtml}}}
       {{else}}
         <div class="topic-error">
           <div>{{message}}</div>
diff --git a/app/assets/javascripts/discourse/views/composer.js.es6 b/app/assets/javascripts/discourse/views/composer.js.es6
index f985345da2c..e76962a56bc 100644
--- a/app/assets/javascripts/discourse/views/composer.js.es6
+++ b/app/assets/javascripts/discourse/views/composer.js.es6
@@ -240,7 +240,7 @@ const ComposerView = Discourse.View.extend(Ember.Evented, {
 
     this.editor = editor = Discourse.Markdown.createEditor({
       lookupAvatarByPostNumber(postNumber) {
-        const posts = self.get('controller.controllers.topic.postStream.posts');
+        const posts = self.get('controller.controllers.topic.model.postStream.posts');
         if (posts) {
           const quotedPost = posts.findProperty("post_number", postNumber);
           if (quotedPost) {
diff --git a/app/assets/javascripts/discourse/views/flag.js.es6 b/app/assets/javascripts/discourse/views/flag.js.es6
index 583452fca48..388735c7c5f 100644
--- a/app/assets/javascripts/discourse/views/flag.js.es6
+++ b/app/assets/javascripts/discourse/views/flag.js.es6
@@ -7,14 +7,21 @@ export default ModalBodyView.extend({
     return this.get('controller.flagTopic') ? I18n.t('flagging_topic.title') : I18n.t('flagging.title');
   }.property('controller.flagTopic'),
 
+  _selectRadio: function() {
+    this.$("input[type='radio']").prop('checked', false);
+
+    const nameKey = this.get('controller.selected.name_key');
+    if (!nameKey) { return; }
+
+    this.$('#radio_' + nameKey).prop('checked', 'true');
+  },
+
   selectedChanged: function() {
-    Em.run.next(() => {
-      this.$("input[type='radio']").prop('checked', false);
+    Ember.run.next(this, this._selectRadio);
+  }.observes('controller.selected.name_key'),
 
-      const nameKey = this.get('controller.selected.name_key');
-      if (!nameKey) { return; }
-
-      this.$('#radio_' + nameKey).prop('checked', 'true');
-    });
-  }.observes('controller.selected.name_key')
+  // See: https://github.com/emberjs/ember.js/issues/10869
+  _selectedHack: function() {
+    this.removeObserver('controller.selected.name_key');
+  }.on('willDestroyElement')
 });