chaos: 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/bin/chaos - from package: emboss

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