Ember-paper: Cannot set property element of [object Object] which has only a getter

I am using Ember-paper 0.2 which seems to be latest stable version. i'm creating navbar learning from tutorial. whenever I add paper-button i am getting error " Cannot set property element of [object Object] which has only a getter".

It looks like i have mistaken some where but not able to figure out what. Below is my code for navbar.

  <div class="md-toolbar-tools">
      
      <div class="paper-right">
                  
      </div>
  </div>

is my logo component below is the component code

<img src="assets/images/logo_sm_app.png" class="logo">

I have defined my styles in app.scss file

I have used steps as stated in the ember-paper documentation. Could you please tell me what is missing? Below is the stack trace of the error i am getting

Uncaught TypeError: Cannot set property element of [object Object] which has only a getter
    at Class.didInsertElement (ripple-mixin.js:31)
    at Class.superWrapper [as didInsertElement] (ember.debug.js:40424)
    at Class.trigger (ember.debug.js:42259)
    at Class.superWrapper [as trigger] (ember.debug.js:40424)
    at CurlyComponentManager.didCreate (ember.debug.js:12725)
    at Environment.commit (ember.debug.js:50904)
    at Environment.commit (ember.debug.js:9283)
    at InteractiveRenderer._renderRoots (ember.debug.js:12121)
    at InteractiveRenderer._renderRootsTransaction (ember.debug.js:12150)
    at InteractiveRenderer._renderRoot (ember.debug.js:12071)