I have a new (clean) install of ISPConfig 3 on Ubuntu Server 16.04. I'm able to successfully connect with SFTP using the FTP user accouts. When the connection is established, it defaults to the user's home directory. I can browse from there to /var/www/clients/client0/web2 at this point when I try to open the /web folder in that directory (to upload files) I get a permission denied / cannot retrieve file listing. I have tested this with 2 different FTP user accounts on 2 different sites on the server and they both have the same permission issue. The owner of the /web folder is web2 (the same account I'm loggin in with), group is client0, and permissions are 711. Any help is appreciated. Thank you.
check your log file (probably /var/log/syslog) for any hints. so you can get to /var/www/clients/client0/web2 in ftp (not sftp) and get a directory listing (hence not a passive ports problem), but can't change to "web" under that? how about "private"? do you have selinux running?