After upgrading to Aria Automation 8.16.2, new deployments can fail at the VM power-on step if the vSphere cluster's DRS setting is set to "Manual".
Error message: "The operation ON failed. The machine [VM_NAME] may be deleted, and cannot be powered on."
Trying to power-on existing (managed) VMs in Aria Automation can also fail with the same error when DRS is set to "Manual".
Fixed in Aria Automation 8.17 and later.
As a workaround, if DRS is changed from "Manual" to "Partially automated" or "Fully automated", then VMs can be successfully powered-on from Aria Automation 8.16.2.