please follows the instruction for the VM MAIN appliance version 1.5
login with username/password as debian/debian from consol
$ pico /etc/network/interfaces
cut char "#" from line "iface eth0 inet dhcp"
and add char "#" on the following lines to obtain:
#iface eth0 inet static
press: Ctrl+x and s to save
then press return to confirm the exit with saving.
Please retart network via:
sudo systemctl restart networking
The correct command may depend on the linux version and kind you are using.
Please note that if you adopt a DHCP approach the Host ETC file has to present the IP address assigned to the VM by the DHCP.
If you use a fixed IP approach, be sure to take a free IP address, and that the VM has only one NIC activated.