nologin: 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 CentOS possible default full paths are:

/sbin/nologin - from package: util-linux-ng

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/nologin - from package: login

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

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