append_sff: 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/append_sff - from package: staden-io-lib-utils

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

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