Our environment is:
- vCenter 6.5 U1g (8024368) running on a Windows Server 2008 R2 Standard VM (we’re moving to an appliance once we go 6.7)
- vSphere 5.5 7504623, 8 node cluster
Since upgrading to the latest vCenter every new VM we clone into our production cluster reports “The virtual machine failed to become vSphere HA Protected and HA may not attempt to restart it after a failure”
After contacting VMware Support they informed me that this is a known issue with the versions of vCenter and vSphere we’re using and to upgrade to vSphere 6.0 or 6.5.
Since vSphere 5.5 is EOL in September no patches are coming to resolve this.
It also turns out the issue is a GUI issue only. The VMs displaying this error are still protected via HA and will recover fine if a host goes down.
A workaround for the issue is to disable/enable HA. Doing so will clear the error.