monopd: 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/monopd - from package: monopd

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