Error when setting up new site

Hi,

I've set up a few live sites in Dreamweaver and these are working fine.

We also have testing sites for these live sites, but every time I try set up a site for them it gives me an error message. The connection details I used for setting these up are the same that I am using when working with FileZilla (and it works fine there). The reason I need to get these sites set up asap is because I need to edit main template files, which then need to update other pages.

Please see the image of the error message attached. We have tried everything , but no success.

Hope there is someone who could help!

Thanks,

Kadri