clfswm: 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/clfswm - from package: clfswm

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

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