Cannot install the vCenter Server agent service. Unknown installer error

[ph4n70m2000]

I am trying to enable HA on my esxi cluster and I get the subjected error when I try to enable HA from one of the hosts. I have tried disconnecting and reconnecting the host, enabling, disabling host but I was not able to get it to install the agent. vxpa log is attached. Any help is greatly appreciated. 

[markey165]

@ph4n70m2000 - Few questions, to aid troubleshooting

• You don't mention which versions. Can you confirm build of vCenter and build of ESXi hosts in use?
• How many ESXi hosts in the Cluster? I wonder if its just one host that has the problem? Dropping each out in turn may be worth a try. Maybe also start with 2 hosts in the Cluster and work from there?
• Are these Physical hosts and are you using a Custom ISO?
• Log into the vCenter VAMI - Does it show Healthy under the Summary Tab? Switch to the Services Tab and sort by Startup Type. Are all services that are set to Automatic showing as healthy and in a running state?

Have a read of these 2 KBs for guidance and additional logs to check

• https://kb.vmware.com/s/article/2056299
• https://kb.vmware.com/s/article/2083945

Although the 2nd link talks about 6.5 it does reference additional log files you probably need to check

HTH

[NateNateNAte]

Agree, we need more details on your environment.  And are you trying to set up HA with ESXi, or the vCS?

Here's also a good article on vCS HA requirements - as well as config and management:

vCenter HA Hardware and Software Requirements (vmware.com)

Hopefully this helps.  Curious to see what other information you can provide so we can help.