zjsdecode: 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/zjsdecode - from package: printer-driver-foo2zjs

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

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