lua50: 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/lua50 - from package: lua50

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

Error in other languages:
lua50: bevel nie gevind nie
lua50: comandă negăsită
lua50: comando não encontrado
lua50: commande introuvable
lua50: command not found
lua50: käsku ei ole
lua50: không tìm thấy lệnh
lua50: komanda nerasta
lua50: Kommando nicht gefunden.
lua50: kommandot finns inte
lua50: komut yok
lua50: nie znaleziono polecenia
lua50: níor aimsíodh an t-ordú
lua50: no se encontró la orden
lua50: no s'ha trobat l'ordre
lua50: opdracht niet gevonden
lua50: parancs nem található
lua50: perintah tidak ditemukan
lua50: príkaz nenájdený
lua50: příkaz nenalezen
lua50: команда не найдена
lua50: командата не е открита
lua50: 命令找不到
lua50: コマンドが見つかりません