mgp2latex: command not found

Have You tried accessing the binary with the full path?

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/mgp2latex - from package: mgp

You may install the required package with command apt-get install {package}
Error in other languages:
mgp2latex: bevel nie gevind nie
mgp2latex: comandă negăsită
mgp2latex: comando não encontrado
mgp2latex: commande introuvable
mgp2latex: command not found
mgp2latex: käsku ei ole
mgp2latex: không tìm thấy lệnh
mgp2latex: komanda nerasta
mgp2latex: Kommando nicht gefunden.
mgp2latex: kommandot finns inte
mgp2latex: komut yok
mgp2latex: nie znaleziono polecenia
mgp2latex: níor aimsíodh an t-ordú
mgp2latex: no se encontró la orden
mgp2latex: no s'ha trobat l'ordre
mgp2latex: opdracht niet gevonden
mgp2latex: parancs nem található
mgp2latex: perintah tidak ditemukan
mgp2latex: príkaz nenájdený
mgp2latex: příkaz nenalezen
mgp2latex: команда не найдена
mgp2latex: командата не е открита
mgp2latex: 命令找不到
mgp2latex: コマンドが見つかりません