I updated vcsa 6.5 to build 4944578 (released 2/2/2017) and the management interface was not working after the update. Poking around I found that the vami-lighttp service startup was failing. Looking further it was complaining it couldn't bind to an IPv6 address. hmmm... Further checking found there were complaints being spit out about the config file. So I checked /opt/vmware/etc/lighttpd/lighttpd.conf and there was a duplicate entry for server.use-ipv6 = "disable", with the 2nd occurrence coming on the last line of the file. I commented this last line out and restarted the service. Bingo, it works.
Including here so anyone else that hits this problem can find my solution.