se_dselect: 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_dselect - from package: policycoreutils

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

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