Codeigniter: Error - call_user_func_array() expects parameter 1 to be a valid callback, class 'Error' does not have a method 'index'

Currently, I want to add new php file in view folder. But, when I add that file, the error display as below even I copied code from the existing file:

Severity: Warning

Message: call_user_func_array() expects parameter 1 to be a valid callback, class 'Error' does not have a method 'index'

Filename: core/CodeIgniter.php

Line Number: 532

Backtrace:

File: /home/spezerco/public_html/orlins/index.php Line: 315 Function: require_once

I already tried look up on the function I created in model and the load code ( $this->loadViews("plan", $this->global, $data, NULL);) but i still can't figure out the problem.

so here is the code:

in CodeIgniter.php line 532: call_user_func_array(array(&$CI, $method), $params);

in index.php line 315: require_once BASEPATH.'core/CodeIgniter.php';