x2gostartagent: 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/bin/x2gostartagent - from package: x2goserver

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

Error in other languages:
x2gostartagent: bevel nie gevind nie
x2gostartagent: comandă negăsită
x2gostartagent: comando não encontrado
x2gostartagent: commande introuvable
x2gostartagent: command not found
x2gostartagent: käsku ei ole
x2gostartagent: không tìm thấy lệnh
x2gostartagent: komanda nerasta
x2gostartagent: Kommando nicht gefunden.
x2gostartagent: kommandot finns inte
x2gostartagent: komut yok
x2gostartagent: nie znaleziono polecenia
x2gostartagent: níor aimsíodh an t-ordú
x2gostartagent: no se encontró la orden
x2gostartagent: no s'ha trobat l'ordre
x2gostartagent: opdracht niet gevonden
x2gostartagent: parancs nem található
x2gostartagent: perintah tidak ditemukan
x2gostartagent: príkaz nenájdený
x2gostartagent: příkaz nenalezen
x2gostartagent: команда не найдена
x2gostartagent: командата не е открита
x2gostartagent: 命令找不到
x2gostartagent: コマンドが見つかりません