grub-installation failed during Ubuntu installation

[Faiyaz Sabik]

I'm trying to install Ubuntu 20.04.6 alongside windows 10. I cleared out an 80 gigs partition (MBR) in hard disk and prepared a bootable usb with ubuntu files (GPT) and initiated the setup. Didn't select the partitions manually, instead chose the Install Ubuntu alongside Windows option in the setup page. Everything went well, but the grub2 package installation failed. Showed an error "Executing 'grub-install'/dev/sd' failed. This is a fatal error."

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity 20.04.15.19
ProcVersionSignature: Ubuntu 5.15.0-67.74~20.04.1-generic 5.15.85
Uname: Linux 5.15.0-67-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.25
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.445.3
CurrentDesktop: ubuntu:GNOME
Date: Mon Jun 26 13:10:16 2023
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 20.04.6 LTS "Focal Fossa" - Release amd64 (20230316)
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)