A PHP Error was encountered

Severity: Notice

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

Filename: controllers/Quiz.php

Line Number: 396

Backtrace:

File: /var/www/html/gogoalsplus/application/controllers/Quiz.php
Line: 396
Function: _error_handler

File: /var/www/html/gogoalsplus/index.php
Line: 324
Function: require_once

Permission Denied!