isodebug: 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 CentOS possible default full paths are:

/usr/bin/isodebug - from package: genisoimage

You may install the required package with command yum install {package}

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