An uncaught Exception was encountered

Type: Error

Message: Call to a member function result() on boolean

Filename: /home/winiadm/public_html/application/models/Model_product.php

Line Number: 82

Backtrace:

File: /home/winiadm/public_html/application/controllers/Product.php
Line: 78
Function: select_product_by_subcategory

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