A PHP Error was encountered

Severity: Warning

Message: Attempt to read property "id" on null

Filename: site/Category_model.php

Line Number: 15

Backtrace:

File: /home/organic3dj83d9c1/public_html/application/models/site/Category_model.php
Line: 15
Function: _error_handler

File: /home/organic3dj83d9c1/public_html/application/controllers/site/Category.php
Line: 24
Function: sub_categories

File: /home/organic3dj83d9c1/public_html/index.php
Line: 315
Function: require_once