Dreamweaver uses your testing server to connect to the database. If you go to the database connection page and click test for your connection what happens?
Is your local server running? Can you connect via phpMyAdmin to the local database? Since this is an issue on your testing server, I'd need to do screen sharing to debug it. If you post your phone number or skype contact information in the private area of a reply, then I can call you and help you figure it out in a quick screen sharing session.