aels: 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/aels - from package: aegis

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

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