Drupal's .htaccess file interferes with some paths built-into MM

MM uses several paths that start with a dot, such as:

http://yoursite.com/.system
http://yoursite.com/.mm-sitemap
http://yoursite.com/.mm-users-json

At the same time, the default .htaccess file that comes with Drupal 7 includes this section, which keeps careless admins from accidentally exposing their source code:

  # If you do not have mod_rewrite installed, you should remove these
  # directories from your webroot or otherwise protect them from being
  # downloaded.
  RewriteRule "(^|/)\." - [F]

This causes the paths listed above to fail in MM. This is most noticeable in the case of /.mm-users-json, which means that it is impossible to view or edit the members of a group in MM.

The solution is to switch to another character instead of a dot. This issue is a reminder that this work needs to be done.

As a temporary workaround for anyone having this problem: you can most likely comment-out this section of your .htaccess file. Just make sure you don't have ".svn", ".git" or similar folders in your site's tree.