RNPxl: 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/RNPxl - from package: topp

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

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