x2goterminate-session: 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/x2goterminate-session - from package: x2goserver

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

Error in other languages:
x2goterminate-session: bevel nie gevind nie
x2goterminate-session: comandă negăsită
x2goterminate-session: comando não encontrado
x2goterminate-session: commande introuvable
x2goterminate-session: command not found
x2goterminate-session: käsku ei ole
x2goterminate-session: không tìm thấy lệnh
x2goterminate-session: komanda nerasta
x2goterminate-session: Kommando nicht gefunden.
x2goterminate-session: kommandot finns inte
x2goterminate-session: komut yok
x2goterminate-session: nie znaleziono polecenia
x2goterminate-session: níor aimsíodh an t-ordú
x2goterminate-session: no se encontró la orden
x2goterminate-session: no s'ha trobat l'ordre
x2goterminate-session: opdracht niet gevonden
x2goterminate-session: parancs nem található
x2goterminate-session: perintah tidak ditemukan
x2goterminate-session: príkaz nenájdený
x2goterminate-session: příkaz nenalezen
x2goterminate-session: команда не найдена
x2goterminate-session: командата не е открита
x2goterminate-session: 命令找不到
x2goterminate-session: コマンドが見つかりません