How many attempts did you allow at Quiz level? Perhaps you bumped onto the quiz scope, since the user left the quiz without finishing the total Quiz
Thanks for reply and thesis.
User has two attempts and if failing grade he has infinity attempts.
What can I do?
Do not understand: are you talking about attempts on Question or on Quiz level? You cannot have both 2 and infinite ?
Have a look at my blog post about question slides, explained the quiz scope there as well:
My settings are:
on Question level - 2 attempts (and 2 failure levels)
on Quiz level - Infinite attempts