boot loader crashes on installation

I'm trying to dual-boot ubuntu 19.10 and windows 10. I created three partitions on my sdb for "/", "/home" and "swap" and then created a "systemgrub" partition on my sda as it was requested to do so.
The installatiob goes well until the last bit where grub starts to install. It gives me a fatal error and a window pops up with three options: choose new location for grub, continue without grub, or cancel installation. I picked continue without grub and the installer gave a message that stated that it crashed and now I'm here.

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: ubiquity 19.10.21 [modified: lib/partman/automatically_partition/question]
ProcVersionSignature: Ubuntu 5.3.0-18.19-generic 5.3.1
Uname: Linux 5.3.0-18-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu8
Architecture: amd64
CasperVersion: 1.427
CurrentDesktop: ubuntu:GNOME
Date: Thu Apr 9 18:51:00 2020
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed initrd=/casper/initrd quiet splash --- maybe-ubiquity
LiveMediaBuild: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
ProcEnviron:
 LANGUAGE=en_ZA.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_ZA.UTF-8
 LC_NUMERIC=C.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)