Just googled this issue, some of people got similar problem, following was my problem and solution, hope it’s useful for you.
Virtual machine maybe lost on vCenter Server inventory for some reason, it’s also disappeared on ESXi inventory when you connect to the individual host directly. You are able to find the VM process by esxcli vm process list, but not able to get it by vim-cmd vmsvc/getallvms.
If you try load the VM manually by commeand vim-cmd vmsvc/reload [vmid], it back you error:
dynamicType = <unset>,
faultCause = (vmodl.MethodFault) null,
msg = “Unable to find a VM corresponding to “vmid””,
You can also find the VM process by esxtop command.
My solution was remove the ESXi host from vCenter Server, then restart management services, and then browse the VM folder, add the VM back to inventory, then join the host back to vCenter Server.