kfountain.kss: 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/kfountain.kss - from package: kscreensaver

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

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