gssdp-discover: 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/gssdp-discover - from package: gupnp-tools

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

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