Error message

• Notice: Undefined index: HTTP_USER_AGENT in include() (line 3 of /var/www/html/D7/docroot/sites/all/includes/settings.php).
• Notice: Undefined index: HTTP_USER_AGENT in include() (line 130 of /var/www/html/D7/docroot/sites/all/includes/settings.local.php).
• HTTP 400; :