knutclient: 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/knutclient - from package: knutclient

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

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