grub-install: error: will not proceed with blocklists
I got this error trying to install Grub2 in a Virtualbox VM that uses an image file as the hard drive. The solution turned out to be using the --force option with grub-install. Even though grub complains about working with blocklists, the VM boots fine now.
sudo grub-install /dev/sda --force
sudo update-grub
grub-install: error: will not proceed with blocklists came up for me when upgrading to 20.04 from 19.10 on a Linode VM, solution was to ignore the error and run
grub-update
and ignore the grub-install error. Seems to boot OK.