Currently I broke the grub. At start up there is a black script with the message:

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

I followed the this post (

However normal.mod is not inside the folder grub:

grub rescue> ls (hd0,msdos6)/boot/grub/

unicode.pf2 x86_64-efi/ locale/ fonts/ grubenv grub.cfg

How could I have my grub menu back?