qmp3check: 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/qmp3check - from package: quelcom

You may install the required package with command apt-get install {package}
Error in other languages:
qmp3check: bevel nie gevind nie
qmp3check: comandă negăsită
qmp3check: comando não encontrado
qmp3check: commande introuvable
qmp3check: command not found
qmp3check: käsku ei ole
qmp3check: không tìm thấy lệnh
qmp3check: komanda nerasta
qmp3check: Kommando nicht gefunden.
qmp3check: kommandot finns inte
qmp3check: komut yok
qmp3check: nie znaleziono polecenia
qmp3check: níor aimsíodh an t-ordú
qmp3check: no se encontró la orden
qmp3check: no s'ha trobat l'ordre
qmp3check: opdracht niet gevonden
qmp3check: parancs nem található
qmp3check: perintah tidak ditemukan
qmp3check: príkaz nenájdený
qmp3check: příkaz nenalezen
qmp3check: команда не найдена
qmp3check: командата не е открита
qmp3check: 命令找不到
qmp3check: コマンドが見つかりません