Bu hata nedir? Sorry! This document can not be checked

w3 sorgulaması yapamıyorum.

Birde altta bir yazı çıkıyor şu şekilde

Sorry, I am unable to validate this document because on line 63 it contained one or more bytes that I cannot interpret as utf-8 (in other words, the bytes found are not valid values in the specified Character Encoding). Please check both the content of the file and the character encoding indication.

The error was: utf8 "\xF0" does not map to Unicode