Page not found (404)

Request Method:	GET
Request URL:	https://supply.lib.sfedu.ru/media/source/%D0%9A%D0%BE%D0%BD%D1%84%D0%B5%D1%80%D0%B5%D0%BD%D1%86%D0%B8%D0%B8/IX%20%D0%BA%D0%BE%D0%BD%D1%84%D0%B5%D1%80%D0%B5%D0%BD%D1%86%D0%B8%D1%8F%2005-09%20%D0%BD%D0%BE%D1%8F%202018/%D0%98%D0%BD%D1%84_%D0%BF%D0%B8%D1%81%D1%8C%D0%BC%D0%BE.docx

"/var/www/localhost/django/booksupply/media/source/Конференции/IX конференция 05-09 ноя 2018/Инф_письмо.docx" не существует

You're seeing this error because you have DEBUG = True in your Django settings file. Change that to False, and Django will display a standard 404 page.