With your help, we're getting a handle on the problem associated with the upgrade. After an upgrade, under conditions we're still investigating, an error is occurring when issuing a start request of the HA service on the upgraded host. When that fails, HA then tries to re-install HA, and the re-install does nothing because the service is already there (and the right version) but we're left without an HA service running.
The work-around is as tjbailey already indicated in this post.
If you don't get results or have any issues, let us know so we can get you back up and running. But your efforts have helped us to identify an issue that we hope to resolve soon.
Thanks.