What did you use to upgrade the host, built in VUM w/in VCSA 6.5, host upgrade baseline and all that jazz? Could have also taken esxcli patch bundle to take it from 6.0U2 to 6.5U1, or autodeploy w/ baked in 10G goodness/vib's. Assuming that is your 10G Intel SFP+ nic/s that is sad on your Xeon-D setup?
Where is it stuck at? Does it reboot/let you back into ESXi 6.0U1 or completely fubared? I'd try a reboot first of that host to see what state or image load it is in unless you are certain it bombed out early.
Fresh load...maybe...hate to say that but there is not a whole lot of config you lose, take ya 15 mins to get set back up. Maybe a good time to investigate/spend some time w/ Host Profiles and AutoDeploy if you are feelin' froggy. :-D