I was trying to overwrite an installation of ubuntustudio 20.04 with a new one.

[Ian McGrath]

I had a lot of trouble booting into the previous installation, so I decided to start over. It was a 500GB SSD, previously having 3 partitions. I was letting the installer erase the disk and it looked like it was going to put it all on partition.This machine has 2 other internal drives, one with windows installed, the other for storage.
The crash happened during the user information step.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity 20.04.15
ProcVersionSignature: Ubuntu 5.4.0-26.30-lowlatency 5.4.30
Uname: Linux 5.4.0-26-lowlatency x86_64
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.445
Date: Fri Jul 24 15:06:19 2020
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntustudio.seed only-ubiquity quiet splash nomodeset ---
LiveMediaBuild: Ubuntu-Studio 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
ProcEnviron:
 LANGUAGE=en_US.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 LC_NUMERIC=C.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)