chkcon: 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/chkcon - from package: sepol-utils

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

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