Installer can't install grub

[PatrickSCarroll]

Installing 17.04 jan 2 2017 build, grub failed to load, installer crashed.

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: ubiquity 17.04.1
ProcVersionSignature: Ubuntu 4.9.0-11.12-generic 4.9.0
Uname: Linux 4.9.0-11-generic x86_64
ApportVersion: 2.20.4-0ubuntu1
Architecture: amd64
CasperVersion: 1.380
Date: Mon Jan 2 22:26:14 2017
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash ---
LiveMediaBuild: Ubuntu 17.04 "Zesty Zapus" - Alpha amd64 (20170102)
ProcEnviron:
 TERM=unknown
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
 LC_NUMERIC=C.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)

[apt-ghetto (apt-ghetto)]

grub-install: error: attempt to install to encrypted disk without cryptodisk enabled. Set `GRUB_ENABLE_CRYPTODISK=y' in file `/etc/default/grub'.

Can you explain your setup in more detail?