A PHP Error was encountered

Severity: Notice

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

Filename: models/School_model.php

Line Number: 743

Backtrace:

File: /home/uniform/html/unimap2/ci/application/models/School_model.php
Line: 743
Function: _error_handler

File: /home/uniform/html/unimap2/ci/application/controllers/School.php
Line: 559
Function: get_random_school

File: /home/uniform/html/unimap2/index.php
Line: 315
Function: require_once