Parrot 5.0 Call for Beta Testers - 2

Same error as I posted for Beta 1.

I tried booting off the ISO again, went into advanced mode console, and tried the following (unsuccessfully):

$sudo su
apt update
apt install grub-pc
(installs)
grub-install /dev/sda
(fails)
mount /dev/sda1 /mnt
mount --bind /dev /mnt/@/dev && mount --bind /dev/pts /mnt/@/dev/pts && mount --bind /proc /mnt/@/proc && mount --bind /sys /mnt/@/sys
chroot /mnt/@
grub-install /dev/sda
(fails)
exit && umount /mnt/@/sys && umount /mnt/@/proc && umount /mnt/@/dev/pts && umount /mnt/@/dev && umount /mnt
shutdown -r now

Next I installed Parrot 5.0 Beta 2 in UEFI mode and it also had grub error.