This doesn't have anything to do with any extensions. It is a problem with dreamweaver itself connecting to your local server and/or database.
The 493 forbidden error might just be that you didn't include a page name with the url and you don't have a default page like index.php set up for your local web server.
If you post a US phone number or Skype contact information I'll give you a call and do screen sharing to debug this with you.