mcxload: 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/mcxload - from package: mcl

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

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