xbcrypt: 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/xbcrypt - from package: percona-xtrabackup

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

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