FTP stopped working on Plesk / Centos

After an update to ProFTPd package, the server (Plesk Panels 11.5.3 on CentOS 6.5) stopped allowing incoming connections. A somewhat awkward situation for active developers, even more so when hosting client websites.

After checking the Xinetd logs at  /var/log/messages we saw the following messages:

Sep 15 20:08:45 xxxx xinetd[1703]: START: ftp pid=3923 from=::ffff:xx.xx.xx.xx
Sep 15 20:08:45 xxxx proftpd[3923]: error: cannot read configuration path '/etc/proftpd.d': Not a directory
Sep 15 20:08:45 xxxx proftpd[3923]: fatal: Include: error including '/etc/proftpd.d/*.conf': Invalid argument on line 95 of '/etc/proftpd.conf'
Sep 15 20:08:45 xxxx xinetd[1703]: EXIT: ftp status=1 pid=3923 duration=0(sec)

It turns out that the update appended the following line to the /etc/proftpd.conf config file:

Include /etc/proftpd.d/*.conf

On the server we was working on that directory didn't exist, thus causing those fatal errors.

So we created the directory it was complaining about and things were back to normal. Here's the command in case:

mkdir /etc/proftpd.d

We then restarted Xinetd with the following command:

/etc/init.d/xinetd restart

Option 2 was to comment out that line in the configuration file. We figured by creating the directory it would make it safer for future updates. 

Hope this helps you...