mididings: 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/mididings - from package: mididings

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

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