xmix: 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/xmix - from package: xmix

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

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