The server does not allow ftp - error 530, why?

Question

FTP

The customer has an ISP-manager as an interface on the server.
I enter the panel using the access granted, but I can no longer connect through the ftp client, although the customer says that he connects via ftp. The server itself gives an error when connecting: "Server response: '530 екоÑÑекÑнÑе даннÑе аÑÑенÑиÑика Ñии
.'"
What could be the reason for such wickedness?
Thanks to all who responded

Answer 1

530 error says wrong password, check what you enter