mprof-decoder: 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/mprof-decoder - from package: mono-profiler

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

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