Why does the 404 url ​​appear when adding a World Map WP?

Question

Search Engine Optimization

Add microdata to the header

<header itemscope itemtype="http://schema.org/WPHeader" id="header" class="header">

when checking in the validator, a link to a non-existent page appears ... as I understand it, the id is picked up and a link is generated .. with id = header

@type	
WPHeader
@id	https://moisait.ru/header
headline	Мой блог
description

How to avoid this without removing the id from the header?

Answer 1

And why do we need micromarking of the header at all, what can it affect, it seems to me that search engines do not support it at all, it’s easier to remove it altogether