Getting an error 550 Local policy requires CCC when trying to get list of files in a folder - FTPS

Question

Error while starting data transfer: Rebex.Net.FtpException: Local policy requires CCC (550).
at Rebex.Net.Ftp.WM(String A, Boolean B, PS C, TP D, Int64 I, FtpTransferState J)
Error while initializing data connection.

Answer 1

It looks like the server is only able to transfer data when the control connection has been reverted to unencrypted mode after a (successful and secure) authentication.

Please try calling ClearCommandChannel method (represents the CCC command) after authenticating and before transfering any files or retrieving directory listings:

var client = new Ftp();
client.Connect("hostname");
client.Login("username", "password");
client.ClearCommandChannel();

Check out Reverting to unencrypted communication for additional information about ClearCommandChannel method.