fp-reg-decryptd: 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-decryptd - from package: flashproxy-facilitator

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

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