debconf-updatepo: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/debconf-updatepo - from package: po-debconf

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