kss2wfk: 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/kss2wfk - from package: abinit

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

Error in other languages:
kss2wfk: bevel nie gevind nie
kss2wfk: comandă negăsită
kss2wfk: comando não encontrado
kss2wfk: commande introuvable
kss2wfk: command not found
kss2wfk: käsku ei ole
kss2wfk: không tìm thấy lệnh
kss2wfk: komanda nerasta
kss2wfk: Kommando nicht gefunden.
kss2wfk: kommandot finns inte
kss2wfk: komut yok
kss2wfk: nie znaleziono polecenia
kss2wfk: níor aimsíodh an t-ordú
kss2wfk: no se encontró la orden
kss2wfk: no s'ha trobat l'ordre
kss2wfk: opdracht niet gevonden
kss2wfk: parancs nem található
kss2wfk: perintah tidak ditemukan
kss2wfk: príkaz nenájdený
kss2wfk: příkaz nenalezen
kss2wfk: команда не найдена
kss2wfk: командата не е открита
kss2wfk: 命令找不到
kss2wfk: コマンドが見つかりません