aesub: 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/aesub - from package: aegis

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

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