MPDCon: command not found

Have You tried accessing the binary with the full path?

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/MPDCon - from package: mpdcon.app

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