FTP over Explicit TLS is the recommended method of connection, because it provides a secure connection between your computer and our server. That’s also the only method of connection encryption that our FTP server supports.
So our server supports AUTH TLS. As for why it doesn’t work, I agree with what the FileZilla developers said on their own forum:
Failure to receive a reply to the AUTH command is almost always the result of a malicious firewall actively sabotaging the connection.
Something on your end is trying to insert itself in the FTP connection, and that doesn’t work with secure connections. You could try contacting your network administrator or ISP about this, or try to work around this with a VPN.
As a last resort, you could also disable secure connections. But be aware that everything points to something sitting in between the connection, so you can assume that your credentials WILL be seen by the attacker and so are all files you’re transferring.
