Why does the webmaster's working page have a size of 0 bytes?

Question

HTML

Good afternoon!
tell me why the Yandex webmaster shows 4 errors from the server side - that is, it writes - "On a page request, your server returned a document of 0 bytes to the robot. For the occurrence and elimination of this problem, please contact your server administrator."
4 pages work on the site. https://yadi.sk/i/VTHoy5InqkCMB
Recently installed a new layout, this is even a continuation of the topic - Why did a lot of 404 errors pop up after installing the new layout?

Answer 1

Have you checked robot.txt?