xconsole: 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/xconsole - from package: xorg-x11-apps

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

On Debian possible default full paths are:

/usr/bin/xconsole - from package: x11-apps

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

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