the MySQL Server name does not look correct to me.
Most hosts will have limitations in place that will make it very difficult to create a connection to the database with in Dreamweaver.
It may be that the host does not even allow for an outside connection to the MySQL database.
because of this, we do not recommend setting up Dreamweaver to connect to the remote MySQL Server for development, we recommend setting up a local testing server for development purposes instead.
doing it this way, you use your local computer as a testing environment, then when you are ready to upload your site to go live, you will only need to change the database connection details to use the remote database.
See the learning resources section:
resources.php?utm_campaign=Forum_header&utm_medium=Forums&utm_source=WebAssistForums
there are tutorial available there for setting up a local testing server, setting up the dreamweaver site and Managing your live database settings