fwflash: 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/fwflash - from package: libnxt

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

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