Error convert img to vdi?

[r43k3n]

I had the same issue. I ended up converting the image using Ubuntu Virtual Machine.

You may want to take a look here:

LEDE 17.01.0-RC1 in VirtualBox

You need to pad the image using something like dd if=original.squashfs.combined.img of=padded.img bs=100m conv=sync before converting it to a vm image.