error trying to generate sitemap for subdirectory

[Smartz]

Hello, I've just generated a sitemap for my domain [external links are visible to admins only] and google has accepted it. Now I'm trying to create one for my wordpress blog [external links are visible to admins only] and I'm getting an error

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


Is it because it's a subdirectory? At this point I'm stumped

[XML-Sitemaps Support]

Hello,

make sure that you submit URL with trailing slash: http://www.domain.com/blog/