We use a backup/recovery solution called esxpress. When we recover our VMs, they essentially put back the original .vmdk and .vmx files. Then you just re-register, and boot.
However our Windows 2008 VMs are failing to boot after recovery. The error in vmware.log is vcpu-0 DecoderIsInvalidInstruction:691 0x8404 #UD fe0ffff sz=2
From other threads, that seems to imply a problem with the vcpu. But the VM is being recovered to the same phsyical esx host that the original VM lived on. So no change in physical hardware.
We're also checking with esxpress. But any ideas on that error message?