My Sitemap wont work in webmaster tools?

I've tried adding the link to my sitemap (http://www.mysite.com/forum/sitemap_index.xml.gz) to google webmaster tools, but i get the error...

General HTTP error: 404 not found
We encountered an error while trying to access your Sitemap. Please ensure your Sitemap follows our guidelines and can be accessed at the location you provided and then resubmit.

What do i need to do to get it working?thanks in advance.

Please try this: Sitmap not found 404

Nope, still doesn't work, anything else i can try?

Please open a ticket with ftp access to check this further.

And how do i open a ticket with ftp access please?

Originally Posted by ttmw

And how do i open a ticket with ftp access please?

Visit the support area : https://www.vbseo.com/tickets/
and Create / Send a new Support Ticket, with the required information.

I am having the same issue. No sitemap and non of the search engines that are being pinged are downloading.