If a remote file in a Contribute site appears to be checked out, but the file isn’t actually locked on the user’s computer, you can unlock the file to enable users to edit it.
When you click any button related to Contribute site administration, Dreamweaver verifies that it can connect to your remote site and that the Site Root URL you’ve given for the site is valid. If Dreamweaver can’t connect, or if the URL isn’t valid, an error message appears.
If the administration tools aren’t working properly, there might be something wrong with the _mm folder.