ktupnptest: 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 CentOS possible default full paths are:

/usr/bin/ktupnptest - from package: ktorrent

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/ktupnptest - from package: ktorrent

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

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