grub crashes on install using xubuntu 18.04

[Jose Luis Florez Castro]

I was installing xubuntu 18.04 from a live usb and I came out that you could not install the grub is a new installation but on the partition where I had installed kubuntu 16.04 I told him to remove it first but God knows if he did well.

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
Date: Mon Sep 10 17:24:47 2018
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/xubuntu.seed boot=casper quiet splash ---
LiveMediaBuild: Xubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)