> installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 10
This error status indicates there is a problem with debconf communication from within this package.
grub-efi-amd64-signed does not invoke debconf itself, but does so via /usr/lib/grub/grub-multi-install.
Can you run 'sudo /usr/lib/grub/grub-multi-install --target=x86_64-efi' manually and see if this command completes successfully?
If it does not, please run 'sudo env DEBCONF_DEBUG=developer /usr/lib/grub/grub-multi-install --target=x86_64-efi' and paste the output.
> installed grub-efi- amd64-signed package post-installation script subprocess returned error exit status 10
This error status indicates there is a problem with debconf communication from within this package.
grub-efi- amd64-signed does not invoke debconf itself, but does so via /usr/lib/ grub/grub- multi-install.
Can you run 'sudo /usr/lib/ grub/grub- multi-install --target= x86_64- efi' manually and see if this command completes successfully?
If it does not, please run 'sudo env DEBCONF_ DEBUG=developer /usr/lib/ grub/grub- multi-install --target= x86_64- efi' and paste the output.