VBoxManage: error: Configuration error: Failed to get the “MAC” value (VERR_CFGM_VALUE_NOT_FOUND)

Failure to start a Virtualbox VM results in the following error:

jonas@yggdrasil:~/EdgeXfoundry$ vboxmanage startvm node-1 –type headless
Waiting for VM “node-1” to power on…
VBoxManage: error: Configuration error: Failed to get the “MAC” value (VERR_CFGM_VALUE_NOT_FOUND)
VBoxManage: error: Details: code NS_ERROR_FAILURE (0x80004005), component ConsoleWrap, interface IConsole

The reason was port forwarding settings for one of the NICs. These settings had been set:

VBoxManage setextradata node-1 “VBoxInternal/Devices/pcnet/0/LUN#0/Config/rpirestinput/Protocol” TCP
VBoxManage setextradata node-1 “VBoxInternal/Devices/pcnet/0/LUN#0/Config/rpirestinput/GuestPort” 48080
VBoxManage setextradata node-1 “VBoxInternal/Devices/pcnet/0/LUN#0/Config/rpirestinput/HostPort” 48080

Removing these settings can be done by using the same commands but without values:

VBoxManage setextradata node-1 “VBoxInternal/Devices/pcnet/0/LUN#0/Config/rpirestinput/Protocol”
VBoxManage setextradata node-1 “VBoxInternal/Devices/pcnet/0/LUN#0/Config/rpirestinput/GuestPort”
VBoxManage setextradata node-1 “VBoxInternal/Devices/pcnet/0/LUN#0/Config/rpirestinput/HostPort”