Installation of Ubuntu 32-bit failed on UEFI

[UlfZibis]

I had the Ubuntu 32-bit installer image on USB-key with MultiSystem.
During the installation I got the error:
Can't copy grub-efi-amd64-signed to /target/

Machine: ASUS F200MA

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubiquity 2.21.63.2
ProcVersionSignature: Ubuntu 4.4.0-31.50-generic 4.4.13
Uname: Linux 4.4.0-31-generic i686
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: i386
CasperVersion: 1.376
Date: Mon Dec 12 02:17:59 2016
InstallCmdLine: BOOT_IMAGE=(loop)/casper/vmlinuz root=UUID=549D-F58A maybe-ubiquity debian-installer/language=de keyboard-configuration/layoutcode= iso-scan/filename=/ubuntu-16.04.1-desktop-i386.iso boot=casper file=/cdrom/preseed/ubuntu.seed noprompt quiet splash --
LiveMediaBuild: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release i386 (20160719)
ProcEnviron:
 LANGUAGE=de_DE.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[UlfZibis (ulf-zibis)]

Workaround: See bug 1648278

[Brian Murray (brian-murray)]

Dec 12 01:11:52 ubuntu ubiquity: System not running in EFI mode, not installing to EFI system partition.
Dec 12 01:11:53 ubuntu ubiquity: efibootmgr: EFI variables are not supported on this system.

[UlfZibis (ulf-zibis)]

My concern is, that ubiquity at least should warn the user at the beginning, instead throwing an error after long time of installing.