A PHP Error was encountered

Severity: Notice

Message: Trying to access array offset on value of type null

Filename: controllers/GoCityController.php

Line Number: 121

Backtrace:

File: /home/y73k8w8goq42/public_html/application/controllers/GoCityController.php
Line: 121
Function: _error_handler

File: /home/y73k8w8goq42/public_html/index.php
Line: 315
Function: require_once