FIX: `topic-admin-menu` controller was not a proper singleton.

app/assets/javascripts/discourse/routes/topic_route.js

@@ -196,6 +196,8 @@ Discourse.TopicRoute = Discourse.Route.extend({
       showExtraInfo: false
     });
 
+    this.controllerFor('topic-admin-menu').set('model', model);
+
     this.controllerFor('composer').set('topic', model);
     Discourse.TopicTrackingState.current().trackIncoming('all');
     controller.subscribe();

app/assets/javascripts/discourse/templates/topic.hbs

@@ -158,5 +158,5 @@
 {{/if}}
 
 {{#if currentUser.canManageTopic}}
-  {{render "topic-admin-menu" content}}
+  {{render "topic-admin-menu"}}
 {{/if}}