ndtpcontrol: 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/sbin/ndtpcontrol - from package: ndtpd

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

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