grub crashes during install of ubuntu 15.10

[sleek]

i am unsure what i did the install disk crashed. i did nothing

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: ubiquity 2.21.37 [modified: lib/partman/automatically_partition/question]
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
ApportVersion: 2.19.1-0ubuntu3
Architecture: amd64
CasperVersion: 1.365
Date: Wed Mar 16 16:15:49 2016
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)

[Phillip Susi (psusi)]

Your disk is partitioned with GPT but you are in a bios booting machine. You need to either boot in UEFI mode or create a 1 mb bios_grub partition on the disk.