ncksteven on "[Plugin: WordPress SEO by Yoast] Sitemap - Error 404 - Page Not Found"

WordPress version:3.5.1
WordPress SEO version:Version 1.4.7

I have installed couponpress & Wordpress SEO and activated the plugin.

It should show sitemap_index.xml but I am getting 404 error

Here is the link http://www.promocouponcode.net/sitemap_index.xml

Can you please help me to resolve this.

Thanks

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