UNABLE TO FTP INTO PLESK SERVER AFTER UPGRADE

If your firewall rules allow access to only specific ports / services as it should be, after a Plesk upgrade clients may struggle to FTP into your server using Passive FTP.

The problem is thatProFTP uses a random set of passive ports to allow incoming connections.

This is what we have done for our clients and ourselves to elliminate the problem.

First open the followng UDP & TCP range on the box  49152-65534

Secondly include this line anywhere in your /etc/proftpd.conf

PassivePorts 49152 65534

Reboot! and all is done.