Ubuntu installer crashed while creating a dual boot on my lenovo g50

[Arun Girisan]

This is preventing me from installing ubuntu

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubiquity 2.21.63.4 [modified: lib/partman/automatically_partition/question]
ProcVersionSignature: Ubuntu 4.10.0-28.32~16.04.2-generic 4.10.17
Uname: Linux 4.10.0-28-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CasperVersion: 1.376.2
Date: Sun Dec 24 12:52:16 2017
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/ubuntu-gnome.seed boot=casper only-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu-GNOME 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
ProcEnviron:
 LANGUAGE=en_IN
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_IN
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)