I have this problem, any idea ?
It may help to say how you installed ERPNext and into what hosting environment. It appears to be a KVM / QEMU setup of some sort.
Download the .ova from the ERPNext page, then unzip it and transform it into a qcow2. Generate a virtual machine in the proxmox(QEMU) and lift the image.
That was the procedure I did … And when I run the image, the ethernet network card is down !!