Merhaba arkadaşlar bir siteme w3 valitaion sitesinden chek ettim şöle bir hata verdi anlamı nedir.

Sorry, I am unable to validate this document because on line 843 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 "\xFE" does not map to Unicode