It works! 🙂 thanks!

problem solved… that was bad nginx config… sorry for disturbing! 🙂
I broke myself and I fixed myself 🙂

UPD2
I have found where error is… problem is in permalinks. When I switch to Default (?p=123) – everything works ok, but after switching to Postname, troubles begin.
Thing is, that I’m using nginx. Can this be a problem reason?

UPD. One more problem. Just tried to log in as non admin user and post something.
There were no problems with posing, but again – problems with editng.
When trying to edit post, I’m receiving an error: “You are not allowed to edit”
Even when I changed user role to Author, I received the same error.
and only when I changed role to Editor, I saw the form, but again withot text.