sks-ecc: 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/sks-ecc - from package: sks-ecc

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

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