simple_consumer3: 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/simple_consumer3 - from package: skytools3

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

Error in other languages:
simple_consumer3: bevel nie gevind nie
simple_consumer3: comandă negăsită
simple_consumer3: comando não encontrado
simple_consumer3: commande introuvable
simple_consumer3: command not found
simple_consumer3: käsku ei ole
simple_consumer3: không tìm thấy lệnh
simple_consumer3: komanda nerasta
simple_consumer3: Kommando nicht gefunden.
simple_consumer3: kommandot finns inte
simple_consumer3: komut yok
simple_consumer3: nie znaleziono polecenia
simple_consumer3: níor aimsíodh an t-ordú
simple_consumer3: no se encontró la orden
simple_consumer3: no s'ha trobat l'ordre
simple_consumer3: opdracht niet gevonden
simple_consumer3: parancs nem található
simple_consumer3: perintah tidak ditemukan
simple_consumer3: príkaz nenájdený
simple_consumer3: příkaz nenalezen
simple_consumer3: команда не найдена
simple_consumer3: командата не е открита
simple_consumer3: 命令找不到
simple_consumer3: コマンドが見つかりません