xml2po: 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 CentOS possible default full paths are:

/usr/bin/xml2po - from package: gnome-doc-utils

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/xml2po - from package: gnome-doc-utils

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

Error in other languages:
xml2po: bevel nie gevind nie
xml2po: comandă negăsită
xml2po: comando não encontrado
xml2po: commande introuvable
xml2po: command not found
xml2po: käsku ei ole
xml2po: không tìm thấy lệnh
xml2po: komanda nerasta
xml2po: Kommando nicht gefunden.
xml2po: kommandot finns inte
xml2po: komut yok
xml2po: nie znaleziono polecenia
xml2po: níor aimsíodh an t-ordú
xml2po: no se encontró la orden
xml2po: no s'ha trobat l'ordre
xml2po: opdracht niet gevonden
xml2po: parancs nem található
xml2po: perintah tidak ditemukan
xml2po: príkaz nenájdený
xml2po: příkaz nenalezen
xml2po: команда не найдена
xml2po: командата не е открита
xml2po: 命令找不到
xml2po: コマンドが見つかりません