ember cli sass ENOTDIR: not a directory, scandir

I'm trying to use ember cli with sass, so i installed the ember-cli-sass, and i'm trying to configure like this:

var EmberApp = require('ember-cli/lib/broccoli/ember-app');

var emberCLIBuild = function(defaults) {
  var app = new EmberApp(defaults, {
    sassOptions: {
      includePaths: [
        'app/styles/admin/main.scss',
        'app/styles/site/main.scss'
      ]
    }
  });

  return app.toTree();
};

module.exports = emberCLIBuild;

but, when i try to run ember serve, the terminal will throw an error:

ENOTDIR: not a directory, scandir '/Users/celicoo/DEV/PubCrawl/Site/tmp/sass_compiler-input_base_path-55sPHD0L.tmp/1/'

How could i fix this? I don't see the problem.

Thanks.