LDAP not starting after restarts

[nadeekas]

After restart our Zimbra server, LDAP is not starting. Below is the error we get. Our Zimbra version is "Release 8.7.11.GA.1854.UBUNTU16.64 UBUNTU16_64 FOSS edition". I need to up this server by tomorrow. Please help me to rectify the issue and put this server back online.

Host mail.example.com
Starting ldap...Done.
Failed.
/opt/zimbra/bin/ldap: line 47: kill: (44271) - No such process
/opt/zimbra/bin/ldap: line 47: kill: (44277) - No such process
/opt/zimbra/bin/ldap: line 47: kill: (44283) - No such process
/opt/zimbra/bin/ldap: line 47: kill: (44289) - No such process
/opt/zimbra/bin/ldap: line 47: kill: (44295) - No such process
/opt/zimbra/bin/ldap: line 47: kill: (44346) - No such process
Failed to start slapd. Attempting debug start to determine error.

In zimbra.log it shows as follows:

Mar 9 02:35:21 mail zimbramon[43608]: 43608:info: Starting services initiated by zmcontrol
Mar 9 02:35:21 mail slapd[44270]: @(#) $OpenLDAP: slapd 2.4.46 (Aug 31 2018 14:52:31) $#012#011build@u1687:/home/build/git/87/packages/thirdparty/openldap/build/UBUNTU16_64/zimbra-openldap/servers/slapd
Mar 9 02:35:27 mail slapd[44276]: @(#) $OpenLDAP: slapd 2.4.46 (Aug 31 2018 14:52:31) $#012#011build@u1687:/home/build/git/87/packages/thirdparty/openldap/build/UBUNTU16_64/zimbra-openldap/servers/slapd
Mar 9 02:35:39 mail slapd[44282]: @(#) $OpenLDAP: slapd 2.4.46 (Aug 31 2018 14:52:31) $#012#011build@u1687:/home/build/git/87/packages/thirdparty/openldap/build/UBUNTU16_64/zimbra-openldap/servers/slapd
Mar 9 02:35:50 mail slapd[44288]: @(#) $OpenLDAP: slapd 2.4.46 (Aug 31 2018 14:52:31) $#012#011build@u1687:/home/build/git/87/packages/thirdparty/openldap/build/UBUNTU16_64/zimbra-openldap/servers/slapd
Mar 9 02:35:57 mail slapd[44294]: @(#) $OpenLDAP: slapd 2.4.46 (Aug 31 2018 14:52:31) $#012#011build@u1687:/home/build/git/87/packages/thirdparty/openldap/build/UBUNTU16_64/zimbra-openldap/servers/slapd
Mar 9 02:36:03 mail slapd[44338]: @(#) $OpenLDAP: slapd 2.4.46 (Aug 31 2018 14:52:31) $#012#011build@u1687:/home/build/git/87/packages/thirdparty/openldap/build/UBUNTU16_64/zimbra-openldap/servers/slapd
Mar 9 02:36:12 mail slapd[44371]: @(#) $OpenLDAP: slapd 2.4.46 (Aug 31 2018 14:52:31) $#012#011build@u1687:/home/build/git/87/packages/thirdparty/openldap/build/UBUNTU16_64/zimbra-openldap/servers/slapd
Mar 9 02:36:23 mail slapd[44470]: @(#) $OpenLDAP: slapd 2.4.46 (Aug 31 2018 14:52:31) $#012#011build@u1687:/home/build/git/87/packages/thirdparty/openldap/build/UBUNTU16_64/zimbra-openldap/servers/slapd