Fresh install from ubuntu 18.04 live cd crashed on GRUB installation

[wastekid]

I am reporting this as a new bug, because I did not do anything custom in the installation wizard.

I only chose pre-defined options in the form of radio buttons and check boxes. A summary of my choices through the wizard:
- I chose the English
- I chose an English keyboard
- I chose a normal installation, i.e. it was not a minimal installation
  - I also checked the box for installing additional drivers, etc.

I believe it was at this point in the wizard that it detected my previous 16.04 installation.

- I chose to remove 16.04 and replace it.

From here, the installation proceeded automatically, until I reached the error.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubiquity 18.04.14.6
ProcVersionSignature: Ubuntu 4.15.0-29.31-generic 4.15.18
Uname: Linux 4.15.0-29-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CasperVersion: 1.394
CurrentDesktop: ubuntu:GNOME
Date: Sun Jan 20 22:19:29 2019
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
ProcEnviron:
 LANGUAGE=en_US.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 LC_NUMERIC=C.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)