Grub error

[perwool]

I am sorry to annonce the bug in grub:

I use debian distro and I cannot finish installation of the actual version 8.4
When the system restart, it falls into the grub rescue > saying:

error: file '/grub/i386-pc/normal.mod' not found

After some googling and after I tried lot of suggested repair advice I found 
following:

the next commands give:
grub rescue > ls                          
(hd0) (hd0,msdos1) (fd0)
 
grub rescue > ls  (hd0,msdos1) 
hd0,msdos1): Filesystem is ext2

grub rescue > ls  (hd0,msdos1)/   
./ ../ lost+found/  etc/  bin/   dev/  home/  lib/     mnt/  proc/ run   srv/  
tmp/  var/
boot/  lib64/  media/  opt/  root/  sbin/  sys/  usr/  vmlinuz  initrd.img 

But command:
grub rescue > ls  (hd0,msdos1)/boot/ 

gives nothing, the same for any other root subdir

Can you have a look at this problem?

Thanks
Jan