SSL error

I run dovecot + postfix as my email server. Everything is working as expected, but I see an error in the dovecot logs:

lmtp(7331): Error: SSL context initialization failed, disabling SSL: ENGINE_init(dynamic) failed

Dovecot is running and emails are OK. I wonder why this error and how I can fix it? I see it is a SSL issue but no idea in which direction to look. Thank you for help