Sitemap is HTML

Hello, after submit my sitemapindex.xml to google it returns that error:

Your Sitemap appears to be an HTML page. Please use a supported sitemap format instead.

I have deactivated some options in plugin but that don’t helped at all. That options is:
– Style your sitemaps with an XSLT stylesheet?
– Show build stats in sitemaps?
– Enable credit?

How can I fix that problem? I don’t know how to make google to like my sitemap. Please answer me ??

My site map hxxp://www.eziny.net/sitemapindex.xml