AdunServer: 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/AdunServer - from package: adun.app

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

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