blend-update-menus: command not found

Have You tried accessing the binary with the full path?

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/sbin/blend-update-menus - from package: blends-common

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