Assertion failed helper when I use custom yields in my application

I'm tryng this solution for my necessity to use two custom yields in same component:

How can I yield multiple pieces of content into an ember.js component template?

This is my code:

// component 

   
    This is a content
  
  
    This is a another content
  


// father-component
<div class="left">
  
</div>
<div class="right">
  
</div>

// foo-content 

In https://ember-twiddle.com/ this works nicelly, but in my localhost this dosn't works and return this error

Assertion Failed: A helper named 'f.right-content' could not be found

Some help?

I work with app exporting the components, and the path js and template separetly