Following an OS upgrade of the server I have been unable to start sshd service. On this server some software is upgraded from the OS packages whereas others are manually built. Openssl is manually built from source. After the upgrade of the OS the error message I get when starting sshd is sshd: undefined symbol: EVP_KDF_ctrl, version OPENSSL_1_1_1b The version I was running was openssl.1.1.1a I then replaced it with openssl.1.1.1d hoping it would resolve the problem. It did not. I would be grateful for any pointers as to how I can resolve this.