stopmotion: 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/stopmotion - from package: stopmotion

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

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