pto_lensstack: 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/pto_lensstack - from package: hugin-tools

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

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