gupnp-network-light: 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/gupnp-network-light - from package: gupnp-tools

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

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