A PHP Error was encountered

Severity: Notice

Message: Trying to get property 'main_id' of non-object

Filename: website/Department_model.php

Line Number: 115

Backtrace:

File: /home/bhospitalbdtask/public_html/application/models/website/Department_model.php
Line: 115
Function: _error_handler

File: /home/bhospitalbdtask/public_html/application/controllers/Departments.php
Line: 68
Function: related_department

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