grub-emu: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/grub-emu - from package: grub-emu

You may install the required package with command apt-get install {package}

Error in other languages:
grub-emu: bevel nie gevind nie
grub-emu: comandă negăsită
grub-emu: comando não encontrado
grub-emu: commande introuvable
grub-emu: command not found
grub-emu: käsku ei ole
grub-emu: không tìm thấy lệnh
grub-emu: komanda nerasta
grub-emu: Kommando nicht gefunden.
grub-emu: kommandot finns inte
grub-emu: komut yok
grub-emu: nie znaleziono polecenia
grub-emu: níor aimsíodh an t-ordú
grub-emu: no se encontró la orden
grub-emu: no s'ha trobat l'ordre
grub-emu: opdracht niet gevonden
grub-emu: parancs nem található
grub-emu: perintah tidak ditemukan
grub-emu: príkaz nenájdený
grub-emu: příkaz nenalezen
grub-emu: команда не найдена
grub-emu: командата не е открита
grub-emu: 命令找不到
grub-emu: コマンドが見つかりません