I'm using this dtd
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">
Error is for this attribute?
<html lang="en">
Should i remove this from DTD?