LDAP: "Unacceptable log file" after db recovery

You'd better use the utilities which shipped in the OpenLDAP package:

$ rpm -ql openldap-servers | grep db_
/usr/sbin/slapd_db_archive
/usr/sbin/slapd_db_checkpoint
/usr/sbin/slapd_db_deadlock
/usr/sbin/slapd_db_dump
/usr/sbin/slapd_db_hotbackup
/usr/sbin/slapd_db_load
/usr/sbin/slapd_db_printlog
/usr/sbin/slapd_db_recover
/usr/sbin/slapd_db_stat
/usr/sbin/slapd_db_upgrade
/usr/sbin/slapd_db_verify

instead of from the db4-utils package:

/usr/bin/db_archive
/usr/bin/db_checkpoint
/usr/bin/db_deadlock
/usr/bin/db_dump
/usr/bin/db_dump185
/usr/bin/db_load
/usr/bin/db_printlog
/usr/bin/db_recover
/usr/bin/db_stat
/usr/bin/db_upgrade
/usr/bin/db_verify