VMware ESXi HA agent failed
If you force problems with reconfigure HA on a ESXi server in a HA Cluster. A possible solution to resolve this is to uninstall the vpxa and the ha-agent. This can be done using the unsupported mode.
Steps:
set ESXi in Maintenance Mode
disconnnect ESXi from Virtual Center
remove ESXi from Virtual Center
connect with SSH to ESXi or direct using something like HP iLo
execute the following commands
cd /opt/vmware/uninstallers/ ./VMware-aam-ha-uninstall.sh ./VMware-vpxa-uninstall.sh
add ESXi to Virtual Center
exit ESXi from Maintenance Mode
repeat this with all Nodes in the cluster