stag-join: 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/stag-join - from package: libdata-stag-perl

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

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