I am using the file manager Altap Salamander with a WinSCP Plugin: https://winscp.net/eng/docs/salamander .
Unfortunately, the plugin is pretty old: "based on WinSCP Version 4.4".
Few days ago, some of our CentOS servers have been updated to version 7.4 and got new openssh version 7.4p1.
Now I cannot log in with that WinSCP plugin of Salamander.
It reports an error "expected key exchange group packet from server".
In the server logs, there are entries "error: kex protocol error: type 30 seq 1 [preauth]" and "Connection closed by xxx.xxx.xxx.xxx port 65476 [preauth]"
After a short investigation, I've found following PuTTY error report: https://community.centrify.com/t5/Centrify-Server-Suite-now-part/Putty-ssh-Keys/td-p/26865 -- perhaps the same or similar issue?
Anyway, the Samalander+WinSCP work fine with the servers which aren't uppdated yet (openssh 6.6.1p1) but not with the updated ones (7.4p1)
Does it mean then that the WinSCP plugin is too old and should be updated, otherwise I will be not able to log in?
Is there a possibility to get it working without downgrading the openssh on the servers?
HELP!..... .... S.O.S. !!...
P.S. PuTTY connects to all servers without any issues.