se_dpkg-reconfigure: 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/sbin/se_dpkg-reconfigure - from package: policycoreutils

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

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