miniupnpd: 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/sbin/miniupnpd - from package: miniupnpd

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

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