natlog: 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/sbin/natlog - from package: natlog

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