Error: No passwd entry for user 'username'

My daughter has a Kano computer kit that she hasn’t used in over a year. I reconnected it to a monitor yesterday to see if my younger son will be interested. It started okay and was working fine until I decided to add my son as an additional user using the option on the dashboard. It said that it needed to reboot to apply changes which I then OKd. Unfortunately after reboot, we now get this error message:

No passwd entry for user ‘username’

Now I’m stuck with a broken Kano and an unhappy and not very impressed son

Any help and advise will be greatly appreciated.

Regards,
Dennis

I would just try a reinstall of the OS:

You should be able to download the latest version for your kit here:

And then follow these instructions here: