Found above after some digging into the matter.Plesk Mobile with (only) secure FTP support
In a Plesk server configured with "Allow only secure FTP" the Mobile App throws the following error: "550 ssl/tls required on the control channel"
Mobile App should connect with secure FTP by default, and if the server does not support secure ftp, then connect with plain text.
Appologies if I sound a bit pushy, but not having an option (of even a default) of a secure connection in the year 2019 is ridiculous.
Even though there is only 5 votes so far, to have a secure connection is a must these days.
Please someone forward this to the Plesk Mobile app devs.
[I did look 5 times forth and back through the app and can't find a way to use/set a secure connection, assuming it's just not available]
Cheers,
Tom
EDIT:
/var/log/secure
lists no attempt at authenticating
/var/log/messages
Jun 5 22:12:06 rhino xinetd[2529]: START: ftp pid=6215 from=::ffff:my.public.ip.address
Jun 5 22:12:08 rhino xinetd[2529]: EXIT: ftp status=0 pid=6215 duration=2(sec)
Last edited: