x2: 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 Debian possible default full paths are:

/usr/bin/x2 - from package: x2

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

Error in other languages:
x2: bevel nie gevind nie
x2: comandă negăsită
x2: comando não encontrado
x2: commande introuvable
x2: command not found
x2: käsku ei ole
x2: không tìm thấy lệnh
x2: komanda nerasta
x2: Kommando nicht gefunden.
x2: kommandot finns inte
x2: komut yok
x2: nie znaleziono polecenia
x2: níor aimsíodh an t-ordú
x2: no se encontró la orden
x2: no s'ha trobat l'ordre
x2: opdracht niet gevonden
x2: parancs nem található
x2: perintah tidak ditemukan
x2: príkaz nenájdený
x2: příkaz nenalezen
x2: команда не найдена
x2: командата не е открита
x2: 命令找不到
x2: コマンドが見つかりません