unable to install grub after installation of OS

[Lokesh Chowdary]

I wanted to install Ubuntu alongside windows 10 but the installer is unable to install grub after the installation of the OS is completed. I previously used to have an Ubuntu 18.04 but I wanted to try Ubuntu Budgie and 19.04 But the Installer is not working. I've tried installing Ubuntu 18.04 & PopOS but it also gives the same error please tell me the solution.Thank You

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: Budgie
Date: Sat Jun 29 18:24:27 2019
InstallCmdLine: file=/cdrom/preseed/ubuntu-budgie.seed boot=casper initrd=/casper/initrd quiet splash --- maybe-ubiquity
LiveMediaBuild: Ubuntu-Budgie 19.04 "Disco Dingo" - Release amd64 (20190416)
ProcEnviron:
 LANGUAGE=en_IN
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_IN
 LC_NUMERIC=C.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)