stl.mpb: 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/lib/ace/bin/MakeProjectCreator/config/stl.mpb - from package: mpc-ace

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