CI-3 HMVC PHP Error

I am trying to get CI-3 to work on localhost with PHP 8.3 and I am getting an error in the MX Controller:

A PHP Error was encountered
Severity: 8192

Message: str_replace(): Passing null to parameter #1 ($search) of type array|string is deprecated

Filename: MX/Controller.php

Line Number: 45

Backtrace:

File: C:\wamp64\www\chichester-evening-as\application\third_party\MX\Controller.php
Line: 45
Function: str_replace

Line 45 is: $class = str_replace(CI::$APP->config->item('controller_suffix'), '', get_class($this));

Any ideas on a fix?