425 Cannot open data connection.

[MxxCon]

Originally posted by Cynyster
Sounds like you do not have the data port open for the ftp server.... if the server is using port 21 port 20 must also be open for data transmittal.... if a nonstandard port is used... the next lower will be the data port.. ie ftp port= 1000 ftp data port will be 999. the same goes for the client side.

that's actualy incorrect.
data port can not be lower than 1025. data port can be anything between 1025-65535. and it has no relation to control connection port number.