jailer: 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/jailer - from package: jailer

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

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