A PHP Error was encountered

Severity: Warning

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

Filename: core/CodeIgniter.php

Line Number: 533

Backtrace:

File: /var/www/html/wbs-webapp/index.php
Line: 301
Function: require_once