I discovered that the score was zero in the questions, I corrected it and the quiz now works.
Unfortunately other quizzes give errors and I find that they have missing values, I can't remember if it was me who didn't write them down.
But the quiz has always had that mistake.

The error appears if I click on the quiz, go down and click the save button, without entering answers.
Except that the browser then stores the error page and doesn't show me the quiz list.
quiz.infermieriattivi.it/index.php?option=com_ariquiz&view=quiz&quizId=367&Itemid=151
quiz.infermieriattivi.it/index.php?option=com_ariquiz&view=quiz&quizId=368&Itemid=151

rgeist: Update the component to v. 3.10.3 please.

Regards,
ARI Soft

will do

Hi,
now the Quiz works, but when I try to change parameters, like the title, I get the message: 0 Class "JArrayHelper" not found

What title do you mean? When open quiz edit page from "Components -> ARI Quiz -> Quizzes" page?

Regards,
ARI Soft

I meant the filed "Name" in Quiz: [Edit]; same error with all fields I tried.