A PHP Error was encountered

Severity: Notice

Message: Undefined index: HTTP_ACCEPT_LANGUAGE

Filename: front/Model_main.php

Line Number: 35

Backtrace:

File: /var/www/html/application/models/front/Model_main.php
Line: 35
Function: _error_handler

File: /var/www/html/application/controllers/Download.php
Line: 32
Function: init

File: /var/www/html/index.php
Line: 315
Function: require_once