Install grub-common by entering the following commands in the terminal:
sudo apt update sudo apt install grub-common
Description:
GRand Unified Bootloader (common files)
This package contains common files shared by the distinct flavours of GRUB. It is shared between GRUB Legacy and GRUB 2, although a number of files specific to GRUB 2 are here as long as they do not break GRUB Legacy.
Homepage: http://www.gnu.org/software/grub/
Version: 2.02-2ubuntu8
Section: admin