SSH Connection Error: buffer_put_cstring: s == NULL [preauth]

I'm trying to connect via SSH to a remote SUSE Linux Enterprise Server 11 from a Windows 10 Computer.

When using Putty 0,73, it works without problems. But using WSL2/Debian I get always refused.

On the Linux Machine, when I open the /var/log/messages file I can see the following line appearing everytime I try to access using WSL2:

Feb 8 12:46:31 remotecomputername sshd[13536]: fatal: buffer_put_cstring: s == NULL [preauth]

On WSL I simply get a Connection closed error:

$ ssh root@ip-of-remote-linux
Connection closed by ip-of-remote-linux port 22

Any ideas what is the problem between the two computers?

Solution 1:

I don't have an answer for the putty part of the problem but from Linux, adding "-c aes256-cbc" to the command line might work. It does for me going from CentOS 8.1 -> SLES11. I have many ancient SLES servers I still need to access in spite of the fact that they "should have" been replaced.