mb2gmn: 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/mb2gmn - from package: gpsman

You may install the required package with command apt-get install {package}
Error in other languages:
mb2gmn: bevel nie gevind nie
mb2gmn: comandă negăsită
mb2gmn: comando não encontrado
mb2gmn: commande introuvable
mb2gmn: command not found
mb2gmn: käsku ei ole
mb2gmn: không tìm thấy lệnh
mb2gmn: komanda nerasta
mb2gmn: Kommando nicht gefunden.
mb2gmn: kommandot finns inte
mb2gmn: komut yok
mb2gmn: nie znaleziono polecenia
mb2gmn: níor aimsíodh an t-ordú
mb2gmn: no se encontró la orden
mb2gmn: no s'ha trobat l'ordre
mb2gmn: opdracht niet gevonden
mb2gmn: parancs nem található
mb2gmn: perintah tidak ditemukan
mb2gmn: príkaz nenájdený
mb2gmn: příkaz nenalezen
mb2gmn: команда не найдена
mb2gmn: командата не е открита
mb2gmn: 命令找不到
mb2gmn: コマンドが見つかりません