stag-view: 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-view - from package: libdata-stag-perl

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

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