Grub install fails during 20.04 install to software RAID 1

[Scott]

Tried hardware RAID 1 without success earlier today. Gave up and tried software install. When Grub2 was beginging to install to EFI partition (as recommended by LTS installer), it ran into a fatal error. (It's been a long day trying to get RAID 1 to work with Desktop 20.04). Will try once more letting the Grub2 use the RAID partition (again, not recommend per the LTS installer). Thanks.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity 20.04.15.2
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.445.1
Date: Tue Aug 11 16:58:00 2020
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)