Snapshots require like to like. You can move from VM to VM or appliance A to appliance A, but you cannot move from VM to appliance A or appliance A to appliance B.
If you're dealing with GWs you can copy over the Gaia clish config as well as other files mentioned in sk160392.
If you're dealing with a SMS/MDS you can copy over the Gaia clish config and do a migrate export/import to move over the management database.
A snapshot would not work in this situation where you are moving from an appliance to a VM though.