I can't comnnect to my web server, I get the message "Inalid server address"

I type in ftp.mydomain.dk and the user name and the password but for some reason
there is something wrong.
It works fine in other FTP clients so I can't see why it is a problem here.

I have tried to change the FTP mode but the problem is the same.

Can some one help me?

Thank you.

Kind regards,
Martin

kind regards, Paul C. Beugeling