PTcrop: 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/PTcrop - from package: libpano13-bin

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

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