When installing, it couldnt install this package grub2... Everything worked perfect until this point

[JANNIS]

So I would like to setup a dual boot with WIN 10 and Ubuntu. But at this step, it keeps failing. I would like to recieve help.

Sincerely, Jannis N

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubiquity 18.04.14.12 [modified: lib/partman/automatically_partition/question]
ProcVersionSignature: Ubuntu 4.18.0-15.16~18.04.1-generic 4.18.20
Uname: Linux 4.18.0-15-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CasperVersion: 1.394
Date: Mon Apr 29 13:50:42 2019
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash ---
LiveMediaBuild: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)