In a hypervisor environment, and cloning a VM from the snapshot of another VM, the new VM booted up fine, but the original VM of which the snapshot was taken was rendered as not bootable. The failure message on boot-up was:
"VM <VM name> is down. Exit message: unsupported configuration: non-primary video device must be type of 'qxl'.
Failed to run VM <VM name> on Host <Hypervisor name>."
There was a chance that the devices from the original VM were not cloned to the new VM but rewritten over the original, which meant the original VM was corrupted. This has been fixed by cloning the devices to the new VM, meaning the original VM will not be corrupted.