November 05, 2008, 10:49 AM — To fix a 'VMware HA failed with error' error message is usually quite simple.
1. First place the offending VMware ESX host into Maintenance Mode evacuating all VMs from the host
2. Drag the ESX host out of the cluster
3. Wait for a just a bit maybe 10 seconds and drag it back into the cluster
These steps will generally fix the message as it will reset VMware HA to remove any artifacts from previous installations. I recently had to perform these steps after a power outage.