wmii9menu: 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/wmii9menu - from package: wmii

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

Error in other languages:
wmii9menu: bevel nie gevind nie
wmii9menu: comandă negăsită
wmii9menu: comando não encontrado
wmii9menu: commande introuvable
wmii9menu: command not found
wmii9menu: käsku ei ole
wmii9menu: không tìm thấy lệnh
wmii9menu: komanda nerasta
wmii9menu: Kommando nicht gefunden.
wmii9menu: kommandot finns inte
wmii9menu: komut yok
wmii9menu: nie znaleziono polecenia
wmii9menu: níor aimsíodh an t-ordú
wmii9menu: no se encontró la orden
wmii9menu: no s'ha trobat l'ordre
wmii9menu: opdracht niet gevonden
wmii9menu: parancs nem található
wmii9menu: perintah tidak ditemukan
wmii9menu: príkaz nenájdený
wmii9menu: příkaz nenalezen
wmii9menu: команда не найдена
wmii9menu: командата не е открита
wmii9menu: 命令找不到
wmii9menu: コマンドが見つかりません