Passive mode ftp requires some or all “unprivileged” (1024-65534) ports to be open on the webserver. The default Plesk firewall configuration blocks all ports except for those single ports required for system services (HTTP, POP, etc.)
To enable passive mode ftp on a Plesk server:
SSH into your server and as root, edit /etc/proftpd.conf.
Add the line in the <global> section:
PassivePorts 60000 65534
* I prefer to limit the number of available ports for greater security.
Login to your Plesk Panel.
Go to Modules -> Firewall to access your firewall configuration.
Select Edit Firewall Configuration.
Add a new Rule:
Name of the rule: FTPD Passive Ports Match direction: Incoming (only) Action: Allow Ports: Add port or port range: 60000-65534 Select TCP Click Add
Click OK and then click Activate (twice)