mia-plugin-help: 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/mia-plugin-help - from package: mia-tools

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

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