freefoam-mhd: 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/freefoam-mhd - from package: freefoam

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

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