Check iptables or other firewall applications running on that machine. If ldap traffic is being blocked, this could be causing it to hang. That’s what happened to me. I changed the firewall rules and forgot to add the ldaps rule and it broke. I could work around it by hitting “i” while booting and it would go into Interactive mode and allow me to say No to the MessageBus service. Everything else came up fine in runlevels 3 and 5, but it would always hang when loading the dbus app.