Usuario o contraseña incorrecta.
Create a quiz (title + video upload), add questions and options (text + image file), then save the quiz to server.
Favor de ingresar un título.
video/ folder.Favor de subir un vídeo.
hh:mm:ss, mm:ss, or plain seconds. JSON stores time as seconds (number). Images are uploaded and stored as img/opt_Q_O.. Only filenames are saved inside questions.json.