title: Unable to locate the specified class: Session.php in Codeigniter
body: <p>The browser: </p>
  
  <p><strong>Unable to locate the specified class: Session.php</strong></p>
  
  <p>This is my Controller:</p>
  
  <pre><code>&lt;?php
  
  class Chat extends CI_Controller {
  
      public function __construct() {
  
          parent::__construct();
          $this-&gt;load-&gt;model('Chat_model');
      }
  
      public function index() {
  
          $this-&gt;view_data['chat_id'] = 1;
          $this-&gt;view_data['student_id'] = $this-&gt;session-&gt;userdata('student_id');
          $this-&gt;view_data['page_content'] = 'chat';
          $this-&gt;load-&gt;view('chat');
      }
  
      public function ajax_addChatMessage() {
  
          $chat_id = $this-&gt;input-&gt;post('chat_id');
          $student_id = $this-&gt;input-&gt;post('student_id');
          $bericht = $this-&gt;input-&gt;post('chat_id', TRUE);
  
          $this-&gt;Chat_model-&gt;addChatMessage($chat_id, $student_id, $bericht);
      }
  }
  </code></pre>
  
  <p>When I put my model in comment in the <code>parent::__construct(); // $this-&gt;load-&gt;model('Chat_model');</code> the error is gone.</p>
  
  <p>This is my Chat_model:</p>
  
  <pre><code>&lt;?php
  
  class Chat_model extends CI_Controller {
  
      public function Chat_model() {
          parent::__construct();
      }
  
      public function addChatMessage($chat_id, $student_id, $bericht) {
  
          $query = "INSERT INTO tbl_chatberichten (chat_id, student_id, bericht) VALUES (?,?,?)";
          $this-&gt;db-&gt;query($query, array($chat_id, $student_id, $bericht));
  
      }
  
  }
  </code></pre>