snnewgroup: 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

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/sbin/snnewgroup - from package: sn

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