After upgrade to Plesk 12, FTP explicite TLS is broken

[MoritzKK]

Unfortunately the encrypted FTP transfer is broken since Plesk upgraded to version 12.
There are two cases:

• Passiv FTP without encryption on port 21: everthing workes fine.
• Passiv FTP with explicite TLS encryption on port 21: The control connection can be established by using TLS on port 21 but the data transfer can't be established by using passive mode (ETIMEDOUT - Connection attempt timed out)

I thought it could be a firewall issue but i'm currently unable to diable the firwall for testing since the configuration of the firewall is unreachable after upgrading to plesk 12! See second thread: http://forum.parallels.com/showthread.php?306397-ERROR-Firewall-configuration

 

[MoritzKK]

It is certainly a firewall issue since the connection to the given random DATA port is possible if the firewall is deactivated at all.
Strangely the problem only appears if TLS is enabled!

 

[chris_cross]

We encountered the same problem.
A solution would be really good.

Clients connecting will throw errors:
425 Unable to build data connection: no route to host