debconf-copydb: 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/debconf-copydb - from package: debconf

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

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