mk_vmgm: 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/mk_vmgm - from package: dvdwizard

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

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