mi: 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/mi - from package: libxgks-dev

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

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