What version of Dreamweaver are you using?
What is the error message you are getting?
if it is the same exact error from the initial post:
2) The testing server specified for this site does not map to the ........... Verify that the URL prefix maps to the root of the site.
then it is definitely a problem with the testing server settings.
Since you are trying to connect to the remote MySQL Server, the testing server settings will need to be set to use FTP to connect to the live server.
In some cases, the ftp connection may connect to a folder bellow the site root. In other words, the connection may put you in a folder bellow what can be accessed by the web URL, you may need to go into a folder such as htdocs or public_html to access the sites index.php page.
If this is the case, make sure to enter that folder in the Root Directory setting of the testing server.
also, make sure the Web URL is the correct URL to access the site root.