Installer crashed while installing to external hdd

[Ravindra Nene]

Disconnected win 10 hdd, booted from usb flash drive (18.04), clicked install, selected external hdd, created partitions, clicked continue, 5 mins through the installation the installer crashed

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubiquity 18.04.14
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CasperVersion: 1.394
CurrentDesktop: ubuntu:GNOME
Date: Wed May 2 15:56:04 2018
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity initrd=/casper/initrd.lz quiet splash ---
LiveMediaBuild: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
ProcEnviron:
 LANGUAGE=en_IN
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_IN
 LC_NUMERIC=C.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Phillip Susi (psusi)]

Your installation medium is corrupt; you will need to recreate it and may want to verify it using the check disc option at the boot menu.