See: https://github.com/sshnet/SSH.NET/issues/956 https://github.com/sshnet/SSH.NET/issues/825#issuecomment-1139440419 Workaround: A simple solution. Add this line in /etc/ssh/sshd_config. PubkeyAcceptedAlgorithms +ssh-rsa Afterwards, restart the sshd service to make the new settings come into effect. $ sudo systemctl restart sshd From: https://unix.stackexchange.com/questions/721606/ssh-server-gives-userauth-pubkey-key-type-ssh-rsa-not-in-pubkeyacceptedalgorit