stag-qsh: 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-qsh - from package: libdbix-dbstag-perl

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

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