Unable to start TLS: SSL connect attempt failed error:

Полное сообщение об ошибке

 Unable to start TLS: SSL connect attempt failed error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed when connecting to ldap master.

Обходное решение

 su - zimbra -c "zmlocalconfig -e ldap_starttls_required=false"
 su - zimbra -c "zmlocalconfig -e ldap_starttls_supported=0"
 su - zimbra -c "zmcontrol start"

Ссылки

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