That is usually an issue with the site settings for the testing server in dreamweaver. You will still need the _mmServerScripts to be created to interact with the database. Our extension overwrites those files with a version that is compatible with php7 and mySQLi.
You could try deleting and recreating those files, but I think the issue is more likely in the Site Settings in Dreamweaver pointing to the wrong url or folder. If you export your site settings and send them to me I can try to reproduce the error and let you know what is going wrong.