title: Meteor : Internal server error [500] with Meteor.methods()
body: <p>I have the collection "menu" with structure:</p>
  
  <pre><code>{
  "_id" : "vJQr7EuieDHMuX2nx" "section" : "vine" "price" : "200" "category" : "bar"
  "_id" : "vJQr7EuieDHMuX4rf" "section" : "beer" "price" : "200" "category" : "kitchen"
  "_id" : "vJQr7EuieDHMuX5tg" "section" : "milk" "price" : "200" "category" : "kbar"
  "_id" : "vJQr7EuieDHMuX4sc" "section" : "beer" "price" : "200" "category" : "kitchen"
  "_id" : "vJQr7EuieDHMuX2xs" "section" : "vine" "price" : "200" "category" : "bar"
  }
  </code></pre>
  
  <p>I want to show the user only "section" without repeating
  For this I used 
  Menu.aggregate([{$group:{_id:"$section"}}]) 
  but it's not working
  How can I do this? May be to use a different method?</p>
  
  <p>Server side:</p>
  
  <pre><code>Meteor.methods({
    'getSections': function () {
      var pipeline = [{$group:{_id:"$section"}}];
      var result = Menu.aggregate(pipeline);
      var sections = [];
      for (i = 0; i &lt; result.length; i++) {
        sections.push(result[i]._id);
      };
      console.log(sections);
      return sections;
    }
  });
  </code></pre>
  
  <p>result in the server: [ 'vine', 'beer', 'milk' ]</p>
  
  <p>Client side:</p>
  
  <pre><code> Template.MobBarMenu.helpers({
          'list': function(){
              this.render('MobBarMenu', {});
          },
          'listSections': function () {
             Meteor.call('getSections', function (err, data) {
                 console.log(data);
                 // return data;
             });
          }
      });
  
  template name="MobBarMenu"
              {{#each listSections}}
                  {{this}}
              {{/each}}
  template
  </code></pre>
  
  <p>I don't know where to find the solution</p>