Corrupted Grub after last reconfigure. How to repair?

[Jone]

Hi all! Last reconfigure passed without errors, but no messages about grub
installation. After reboot - grub rescue prompt. For example, some command
output in rescue console:
insmod search
# ok, silent
insmod linux
error: symbol 'some_symbol' not found

cd /mnt/boot/; ls -R
.:
grub
./grub:
fonts  grub.cfg  grubenv  i386-pc  locale  themes
./grub/fonts:
unicode.pf2
./grub/i386-pc:
acpi.mod     gcry_blowfish.mod  lzopio.mod  .. # and other modules
./grub/locale:
ast.mo  address@hidden  address@hidden .. # and other locales
./grub/themes:
starfield
./grub/themes/starfield:
blob_w.png  boot_menu_sw.png README .. # other files

I was able to boot from liveCD Antix and cannot boot from any usb device,
despite the fact that the BIOS is set the boot order as first: DVD-ROM ->
second: removable dev -> last: system SSD (with GuixSD and /boot
directory). What opinions?