I was in the process of configuring HA when I received an alert "HA agent has an error" on 1 (one) of 3 (three) hosts. I notified Tech Support and they instructed me to remove the ESX server from the cluster (to remove the agents). The host has been "In Progress" for the last 3 (three) hours. Any ideas?
Cancel it, disable HA, try removing the host again, re-add it to the inventory and re-enable HA. This has happened to me a couple of times, don't know why though.
Might also try restarting your virtual center service on the virtual center server itself.