A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_REFERER

Filename: models/Xsendfile_model.php

Line Number: 29

Backtrace:

File: /var/www/vhosts/serverkursu.com/httpdocs/application/models/Xsendfile_model.php
Line: 29
Function: _error_handler

File: /var/www/vhosts/serverkursu.com/httpdocs/application/controllers/Project_server_media.php
Line: 732
Function: model

File: /var/www/vhosts/serverkursu.com/httpdocs/index.php
Line: 317
Function: require_once