Hello Oleg,

The Ubuntu package uses GnuTLS and therefore your olcTLSCipherSuite setting needs to contain a valid GnuTLS priority string.

https://gnutls.org/manual/html_node/Priority-Strings.html

The slapd crash you are seeing is an Ubuntu-specific bug and has been fixed in later versions.

https://bugs.launchpad.net/bugs/1103353

If you configure a valid GnuTLS priority string, it will not crash.

In future please report issues with distro packages to the distro's bug tracker (in this case Launchpad); we can always forward them here if appropriate.

This ITS will be closed.