VBoxManage: error: VBoxNetAdpCtl: Error while adding new interface: failed to open /dev/vboxnetctl: No such file or directory code example

Example: vboxnetadpctl: error while adding new interface: failed to open /dev/vboxnetctl: no such file or directory.

I'm running macOS High Sierra 10.13.1 and VirtualBox 5.2.2.

This worked for me:
Grant permission to VirtualBox under System Preferences > Security & Privacy > General (this request is new to macOS High Sierra)
Open Terminal and run: sudo "/Library/Application Support/VirtualBox/LaunchDaemons/VirtualBoxStartup.sh" restart