scls: command not found

Have You tried accessing the binary with the full path?

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/scls - from package: libsc-dev

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