xpp: 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/xpp - from package: xpp

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

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