9menu: 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/bin/9menu - from package: 9menu

You may install the required package with command apt-get install {package}
Error in other languages:
9menu: bevel nie gevind nie
9menu: comandă negăsită
9menu: comando não encontrado
9menu: commande introuvable
9menu: command not found
9menu: käsku ei ole
9menu: không tìm thấy lệnh
9menu: komanda nerasta
9menu: Kommando nicht gefunden.
9menu: kommandot finns inte
9menu: komut yok
9menu: nie znaleziono polecenia
9menu: níor aimsíodh an t-ordú
9menu: no se encontró la orden
9menu: no s'ha trobat l'ordre
9menu: opdracht niet gevonden
9menu: parancs nem található
9menu: perintah tidak ditemukan
9menu: príkaz nenájdený
9menu: příkaz nenalezen
9menu: команда не найдена
9menu: командата не е открита
9menu: 命令找不到
9menu: コマンドが見つかりません