cant start isc-dhcp-server6

[Denis Taranushin]

Hello.
I use DHCP + LDAP. They works well.
But after reboot i have

Jun 15 14:16:57 dhcp1 slapd[1018]: @(#) $OpenLDAP: slapd  (Ubuntu) (Sep 
15 2015 18:19:13) 
$#012#011buildd at lgw01-53:/build/openldap-2QUgtL/openldap-2.4.31/debian/build/servers/slapd

Jun 15 14:16:57 dhcp1 dhcpd: Error: Cannot login into ldap server 
127.0.0.1:389: Can't contact LDAP server

Jun 15 14:16:57 dhcp1 dhcpd: Configuration file errors encountered -- 
exiting

slapd starts but dhcpd can't connect. If I run manually:
service isc-dhcp-server6 start
the server starts normally

also i have errors inb log:
kernel: type=1400 audit(1465987873.009:24): apparmor="DENIED" 
operation="mknod" profile="/usr/sbin/dhcpd" name="/tmp-sDNmo4KlSV" 
pid=1272 comm="dhcpd" requested_mask="c" denied_mask="c" fsuid=0 ouid=0

"/tmp-sDNmo4KlSV"  is strange.

any ideas?