Include Virtual (SSI) from root .ru/ works, but not from index.html! What is the problem?

Question

linux

I do <!--#include virtual="/inc/file.html" -->
From the root domen.ru/ it works, but already from domen.ru/index.html it doesn't!
well, from all the files domen.ru/file2.html, domen.ru/file3.html does not work.
Only if you type domen.ru/ then it works....
It's written in htaccess
AddHandler server-parsed .html
On another server, it all worked fine.