x2goshowblocks: 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/x2goshowblocks - from package: x2goserver

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

Error in other languages:
x2goshowblocks: bevel nie gevind nie
x2goshowblocks: comandă negăsită
x2goshowblocks: comando não encontrado
x2goshowblocks: commande introuvable
x2goshowblocks: command not found
x2goshowblocks: käsku ei ole
x2goshowblocks: không tìm thấy lệnh
x2goshowblocks: komanda nerasta
x2goshowblocks: Kommando nicht gefunden.
x2goshowblocks: kommandot finns inte
x2goshowblocks: komut yok
x2goshowblocks: nie znaleziono polecenia
x2goshowblocks: níor aimsíodh an t-ordú
x2goshowblocks: no se encontró la orden
x2goshowblocks: no s'ha trobat l'ordre
x2goshowblocks: opdracht niet gevonden
x2goshowblocks: parancs nem található
x2goshowblocks: perintah tidak ditemukan
x2goshowblocks: príkaz nenájdený
x2goshowblocks: příkaz nenalezen
x2goshowblocks: команда не найдена
x2goshowblocks: командата не е открита
x2goshowblocks: 命令找不到
x2goshowblocks: コマンドが見つかりません