mconnect-io: 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/mconnect-io - from package: ucspi-tcp-ipv6
/usr/bin/mconnect-io - from package: ucspi-tcp

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

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