title: ElasticSearch C# client (NEST): Filtering results with ES 5.5.0
body: <p>This was my code in the earlier version of ES it used to work. After moving to ES 5.5. It has stopped working and it gives a compiler error.</p>
  
  <p>Error: 'QueryStringQueryDescriptor' does not contain a definition for 'OnFields' and no extension method 'OnFields' accepting a first argument of type 'QueryStringQueryDescriptor' </p>
  
  <p>Below is my code snippet...</p>
  
  <pre><code>    public List&lt;EmployeeInfo&gt; SearchText2(string query, List&lt;string&gt; sendersList, int page = 0, int pageSize = 50)
      {
          try
          {
  
              var result = this.client.Search&lt;EmployeeInfo&gt;(s =&gt; s
                   .From(page * pageSize)
                   .Size(int.MaxValue)
                   .Query(q =&gt; q
                              .QueryString(qs =&gt; qs.Query(query).UseDisMax()
                              .OnFields(b =&gt; b.Subject)
                              .OnFields(b =&gt; b.Body)
                              ))
                  .SortDescending(f =&gt; f.ReceivedTime)
                   .Filter(f =&gt; f.Terms(ak =&gt; ak.SenderName, sendersList))
  
                              );
  
                     ...
                     // Some code here
  
          }
  </code></pre>
  
  <p>Any tips on how to make this work will be great.</p>