Error when reflashing J1020

Hi all,
I’m trying to reflash my reComputer J1020 following carefully this guide reComputer J1020 | A206 | Seeed Studio Wiki but it keeps failing when installing. Here is a screenshot of the terminal:

Do you have an idea of what I’m doing wrong? I am following the guide very carefully.

actually the problem was given by “apt-get update” not working on the host PC