Codeigniter 3 HMVC has been broken

Using this HMVC plugin in Codeigniter. (https://bitbucket.org/wiredesignz/codeig...niter-3.x/)

Running fine in another server, but in this server I am getting this error!

A PHP Error was encountered

Severity: 8192

Message: strpos(): Non-string needles will be interpreted as strings in the future. Use an explicit chr() call to preserve the current behavior

Filename: MX/Router.php

Line Number: 239

Backtrace:

File: /var/www/project.test/public/application/third_party/MX/Router.php
Line: 239
Function: strpos

File: /var/www/project.test/public/application/third_party/MX/Router.php
Line: 101
Function: _set_default_controller

File: /var/www/project.test/public/index.php
Line: 324
Function: require_once