VirtualBox natnetwork start failed

I use VirtualBox 5.0.16_Ubuntu, Ubuntu 16.04. When I added a new NAT network and try to start natnetwork service, I got some error: ~$ VBoxManage natnetwork add --netname openstack --network "192.168.15.0/24" --enable --dhcp off ~$ VBoxManage natnetwork start --netname openstack VBoxManage: error: Code NS_ERROR_FAILURE (0x80004005) - Operation failed (extended info not available) VBoxManage: error: Context: "Start(Bstr("whatever").raw())" at line 408 of file VBoxManageNATNetwork.cpp VBoxManage: error: Failed to start network What can I do with it?