mppl: 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/mppl - from package: makepp

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

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