That is very strange. Simply reinstalling grub without making any other changes should not have had any different outcome. An EFI system must have an EFI system partition mounted in /boot/efi. The original error message is complaining that it can not find that.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1653982 Title: grub-install post installation script fails To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub-installer/+bug/1653982/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs