I think you're running into a support issue. VirtualBox is not a supported hypervisor and that message appears when the code doesn't recognize the hardware.
If you had this error on an appliance, it would mean that the BIOS had been wiped and the fix would be to RMA the hardware. Good thing it's your lab!
While it is unsupported, it's possible it's related to an issue we're having and Engineering is reviewing. We run our environment on Linux KVM and after 10.0, we've been unable to upgrade due to a missing driver in the ramdisk. There are a couple things you could try to get it working for the time being. The first is to try different setting for the virtual disk. I'm not familiar with Virtual Box, but try changing the drive type. We typically run ours as VirtIO in KVM, but part of the driver for that is missing. If we switch to IDE, we can boot, but there's a performance hit. The other option is to boot with a previous version of the kernel. Neither are long term solutions, but if you're just trying to get a lab to run to look at the new features/fixes, this may help.
Much Thanks for the help Andy and Akerr,
I was able to upgrade the ESM after change to SCSI controller to IDE controller.