Incorrect namespace in Sitemap
<p>I am getting this error on google search console. I tried bunch of things but nothing worked. Any suggestion if i am missing something. </p>

<p>Description: Your Sitemap or Sitemap index file doesn't properly declare the namespace.</p>

<p>Example: Your Sitemap or Sitemap index file doesn't declare the expected namespace: <a href="http://www.sitemaps.org/schemas/sitemap/0.9" rel="nofollow">http://www.sitemaps.org/schemas/sitemap/0.9</a>
Tag: urlset</p>

<p>This is what i see on the sitemap:</p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8" standalone="yes"?&gt;&lt;urlset xmlns:Xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"&gt;
</code></pre>

<p>My Code: </p>

<pre><code>public XmlSitemapResult(IEnumerable&lt;ISitemapItem&gt; items)
        {
            _items = items;
        }

        public override void ExecuteResult(ControllerContext context)
        {
            string encoding = context.HttpContext.Response.ContentEncoding.WebName;
            XDocument sitemap = new XDocument(new XDeclaration("1.0", "utf-8", "yes"),
                 new XElement("urlset", new XAttribute(XNamespace.Xmlns.GetName("Xmlns"), "http://www.sitemaps.org/schemas/sitemap/0.9"),
                      from item in _items
                      select CreateItemElement(item)
                      )
                 );

            context.HttpContext.Response.ContentType = "text/xml";
            context.HttpContext.Response.Flush();
            context.HttpContext.Response.Write(sitemap.Declaration + sitemap.ToString());
        }
</code></pre>