gmpc-remote: 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/gmpc-remote - from package: gmpc

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

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