fp-reg-decrypt: 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/fp-reg-decrypt - from package: flashproxy-facilitator

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

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