After a HA failover event you see a warning message for a cluster in your vCenter Server/webclient:
“HA initiated a failover on …”
Unfortunately there is no option to remove or acknowledge the message. The only possibility to get rid of the message is to disable and re-enable HA for the cluster.
There exists an KB article about this issue, too: Unable to remove warning message in cluster in VMware vCenter Server 4.x/5.x: HA failover initiated on <clustername> (2004802)