update-menus: 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/update-menus - from package: menu

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

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