prrt-navigator-demo: 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/prrt-navigator-demo - from package: mrpt-apps

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

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