The complete Installation runs smooth on one machine that is not behind a Firewall.
Configuration is as
Encryption: TLS/SSL Explicit
If started behind firewall on a different Server i get the follwing error messages after starting login on the Windows client:
Command not implemented.
Port 21 is supposed to be open in Firewall. Could there be any other reason for this messages?
And yes I searched already for this error messages and didnt find any hint where to look for next.
Any help appreciated.