By default the add-on is limited to the php document root. If you want to have full access to your entire file system you can enter the following url in your address bar:
https://www.example.com/index.php/bitter/file_manager/full_access/allow
To turn on the protection again just enter this url in your browsers address bar:
https://www.example.com/index.php/bitter/file_manager/full_access/disallow
