odjinud on "[Plugin: WordPress SEO by Yoast] BWP Google XML Sitemaps Error: Requested module (sitemap_index) not found"

Hi,
WordPress SEO is great plugin, but I can't find http://subdomain.domain.com/sitemap_index.xml .

BWP Google XML Sitemaps Error: Requested module (sitemap_index) not found or not allowed.

Is there some .htaccess "WordPress SEO - XML Sitemap Rewrite Fix" for this case of subdomain.domain.com?

Thanks for your help!

http://wordpress.org/extend/plugins/wordpress-seo/