A PHP Error was encountered

Severity: Notice

Message: Undefined index: user_id

Filename: pages/product-page.php

Line Number: 508

Backtrace:

File: /home/ralchah/public_html/application/views/front-end/classic/pages/product-page.php
Line: 508
Function: _error_handler

File: /home/ralchah/public_html/application/views/front-end/classic/template.php
Line: 59
Function: view

File: /home/ralchah/public_html/application/controllers/Products.php
Line: 342
Function: view

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