I'm also hitting this problem against a Secure Transport 5.2.1 FTP server over which I have no control.
Would it be possible to check that the OPTS command is supported before calling SetTextEncoding(ETextEncoding.UTF8) in FTPSClient.cs?
Would it be possible to check that the OPTS command is supported before calling SetTextEncoding(ETextEncoding.UTF8) in FTPSClient.cs?