Installer crashed while updating grub

[Brad Wiley]

While trying to install Ubuntu 19.4, everything is fine until installing grub. An unknown error causes the installer to crash and not install grub.

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: ubiquity 19.04.9
ProcVersionSignature: Ubuntu 5.0.0-13.14-generic 5.0.6
Uname: Linux 5.0.0-13-generic x86_64
ApportVersion: 2.20.10-0ubuntu27
Architecture: amd64
CasperVersion: 1.405
CurrentDesktop: ubuntu:GNOME
Date: Tue Jul 23 09:01:43 2019
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash oem-config/enable=true ---
LiveMediaBuild: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
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)