It's impossible to install grub.

[karolus]

The error is: "grub-install error cannot open directory /boot/grub/386-pc". My system in 64 bit and I don't understand the reason why the error is on 386 pc...

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: ubiquity 21.04.17
ProcVersionSignature: Ubuntu 5.11.0-14.15-generic 5.11.12
Uname: Linux 5.11.0-14-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu65
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.461
Date: Sun Apr 18 17:10:59 2021
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu-budgie.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu-Budgie 21.04 "Hirsute Hippo" - Beta amd64 (20210417)
RebootRequiredPkgs:
 linux-image-5.11.0-14-generic
 linux-base
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)