a2jmidi_bridge: 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/a2jmidi_bridge - from package: a2jmidid

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

Error in other languages:
a2jmidi_bridge: bevel nie gevind nie
a2jmidi_bridge: comandă negăsită
a2jmidi_bridge: comando não encontrado
a2jmidi_bridge: commande introuvable
a2jmidi_bridge: command not found
a2jmidi_bridge: käsku ei ole
a2jmidi_bridge: không tìm thấy lệnh
a2jmidi_bridge: komanda nerasta
a2jmidi_bridge: Kommando nicht gefunden.
a2jmidi_bridge: kommandot finns inte
a2jmidi_bridge: komut yok
a2jmidi_bridge: nie znaleziono polecenia
a2jmidi_bridge: níor aimsíodh an t-ordú
a2jmidi_bridge: no se encontró la orden
a2jmidi_bridge: no s'ha trobat l'ordre
a2jmidi_bridge: opdracht niet gevonden
a2jmidi_bridge: parancs nem található
a2jmidi_bridge: perintah tidak ditemukan
a2jmidi_bridge: príkaz nenájdený
a2jmidi_bridge: příkaz nenalezen
a2jmidi_bridge: команда не найдена
a2jmidi_bridge: командата не е открита
a2jmidi_bridge: 命令找不到
a2jmidi_bridge: コマンドが見つかりません