PTmasker: command not found

Have You tried accessing the binary with the full path?

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/PTmasker - from package: libpano13-bin

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