Installation always crashes on part when it installs grub2

[Aleksa Prtenjaca]

I had Ubuntu installed on my hard disk before and Kali Linux and Windows on my SSD. I deleted Kali and Ubuntu and decided to install Ubuntu on SSD. Then i probably did something wrong, so I ended with not being able to run Windows from Boot Menu, only grub would start. All Windows files were there, but i couldn't start it. Then I simply formatted the whole SSD and installed Windows again. I shrank C: and left 50GB of Unallocated Space for Ubuntu. Before all of that, I downloaded Ubuntu 18.04.1 LTS and put it on USB using Rufus. I have EFI partition on my SSD, so in Ubuntu installation i only added /, swap area and /home. I tried many other things, but none worked. I would really appreciate your help.

Regards,
Aleksa Prtenjaca

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: Sat Dec 1 22:37:08 2018
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)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.