Ubuntu won't install bootloader to /dev/sda. UEFI crap

[Brian Erwin]

I'm trying to dual boot Ubuntu 15.10 with windows 10. I have turned off fast boot in windows, and am at my wits end. I'm about to go back to fedora and give that a try. Hopefully, this UEFI crap gets resolved, and I can come back to Ubuntu.

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: Mon Jan 18 22:48:18 2016
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --- maybe-ubiquity
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)]

You booted the installation cd in bios mode instead of UEFI mode. You need to boot it in UEFI mode.