remuco-mplayer: 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/remuco-mplayer - from package: remuco-mplayer

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