gnome-pty-helper: 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:

/usr/sbin/gnome-pty-helper - from package: gnome-libs

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

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