psbl: 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/psbl - from package: impose+

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

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