Full_Name: Christian B.sch Version: 2.4.42 OS: FreeBSD 10.2 URL: ftp://ftp.openldap.org/incoming/ Submission from: (NULL) (2001:628:2130:4458::93)
I installed OpenLDAP 2.4.42, enabled these overlays on the mdb database: olcOverlay={0}syncprov.ldif olcOverlay={1}dds.ldif olcOverlay={2}accesslog.ldif olcOverlay={3}unique.ldif olcOverlay={4}ppolicy.ldif olcOverlay={5}refint.ldif olcOvery%y={6}memberof.ldif olcOverlay={7}dynlist.ldif started, everything is fine.
Then I added an empty base tree: dn: dc=example,dc=net objectClass: dcObject objectClass: organization o: ORG dc: example
dn: cn=admin,dc=example,dc=net objectClass: organizationalRole cn: LDAP Admin cn: admin
dn: o=org,dc=example,dc=net o: ORG objectClass: organization objectClass: top
After that, if slapd is restarted: /usr/local/etc/rc.d/slapd: WARNING: failed to start slapd
If the db files are removed again, the startup works again, and if the dds overlay is removed the startup is always working even if the database isn't empty.