My problem was, during upgrade process from 8.10 a dependency (in my case debian-edu-artwork) remove the grub package and without this the post-installation script don't execute grub-upgrade.
I solved in this mode: manually removed debian-edu-artwork and reinstalled grub from synaptic.
My problem was, during upgrade process from 8.10 a dependency (in my case debian-edu-artwork) remove the grub package and without this the post-installation script don't execute grub-upgrade.
I solved in this mode: manually removed debian-edu-artwork and reinstalled grub from synaptic.