SYMPTOMS
A client has .htaccess file right under httpdocs directory. This file can be seen in the Plesk file manager, but it is not shown if you access the site via FTP.CAUSE
Files that begin with dot are hidden in the UNIX environment by default. The same rule works if you access them via FTP.RESOLUTION
If you use command line FTP client, you can run the "ls -al" command and it will show all files. Also, some FTP clients provide an option by which one can "unhide" hidden files via a preference setting.Another way, you can set FTP server to always show files that begin from dots by editing /etc/proftpd.conf, add the line:
ListOptions "-A" Keywords: ftp client hidden files .htaccess dot