A PHP Error was encountered

Severity: Warning

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

Filename: models/Get_model.php

Line Number: 54

Backtrace:

File: /home/goodmeat1/public_html/application/models/Get_model.php
Line: 54
Function: _error_handler

File: /home/goodmeat1/public_html/application/controllers/Mycart.php
Line: 27
Function: getUserName

File: /home/goodmeat1/public_html/index.php
Line: 315
Function: require_once