Can't open existing file

Hello

I have done a lot of work creating a new web site and everything has been working fine for the last week. Worked on it again yesterday but today it won't open up and I get the attached messages. Help please. The site has been publised to test space on the web at http://www.intelligentbrochures.com/ruby2010. Any thoughts on what has gone wrong and how to recover it will be most welcomed.

Thanks
Charles

What file type are you trying to open that's causing that message?

To make changes to your website you need to open the .web or .xar file that you used to initially design it, then re-export your site once done.