Cannot get past step 1

[puppetpimp]

Hello,
I've tried multiple xml sitemap generators and none of them can even begin to index my website: [external links are visible to admins only]

When using this generator I get:

An error occured

There was an error while accessing the URL specified: [external links are visible to admins only]
Please make sure to specify the correct website URL and resubmit your request.

I even tried [external links are visible to admins only]

any ideas? There is no report of malware on the site according to google webmaster tools

[XML-Sitemaps Support]

Hello,

your site homepage returns http code 500, and although it renders correctly in browsers, bots will not index it:
http://www.xml-sitemaps.com/http-headers-viewer.html?op=http-headers-viewer&go=1&pageurl=http%3A%2F%2Fwww.cpmedicalwear.com%2F&se=xmlsitemaps&submit=View