Using vSphere 5.5 with NetVault Backup plugin for VMware 2.7.x, a restore can fail with the following error:
Error Failed to add VM to target server's inventory
More detail on that message, as well as tracing, will show:
VMWVIM :Fault string is 'Invalid configuration for device '3'.'
VMWVIM :Fault type is 5005
VMWVIM :Property name is info.state and change type is 2
VMWVIM :Property value type is 58
VMWVIM :Property value is 3
VMWVIM :Expected: 280
VMWVIM :Received: -1
VMWVIM :Task failed: TRUE
VMWVIM :Done: TRUE
VMWVIM :Destroying the property filter
VMWVIM :Destroyed the filter
VMWVIM :Failed wait for CreateVM_Task
VMWVIM :Failed to create VM from config info
VMWRESTR:Failed to add VM to server inventory