Array To String error / undefined $query

The error seems to be in your MY_Controller file, which is most likely in your application/core folder.
Please check what it does at line 24.

Code:

class MY_Controller extends CI_Controller
{
 protected $data = array();
 function __construct()
 {
   parent::__construct();
   $this->data['page_title'] = 'SIIGA';
   $this->data['before_head'] = '';
   $this->data['before_body'] ='';
 }

 protected function render($the_view = NULL, $template = 'master')
 {
   if($template == 'json' || $this->input->is_ajax_request())
   {
     header('Content-Type: application/json');
     echo json_encode($this->data);
   }
   else
   {
     $this->data['the_view_content'] = (is_null($the_view)) ? '' : $this->load->view($the_view,$this->data, TRUE);;
     $this->load->view('templates/'.$template.'_view', $this->data);

This is MY_Controller file. Line 24 is //

Code:

     $this->load->view('templates/'.$template.'_view', $this->data);