In mod_quiz, the number of attempts can be checked using the Results option from the quiz options. On that page, it is possible to select multiple attempts to delete them. The delete attempt pop-up was using M.util.show_confirm_dialog which is deprecated and for releases 3.11 onwards, it stopped responding to that event.

Steps to reproduce:

1. Navigate to a course.
2. Create a quiz.
3. Attempt the quiz as a student or switch role to a student before attempting the quiz.
4. Go to quiz > results > select the appropriate report options and click Show report
5. Select the attempt
6. Click Delete selected attempts
7. You will see the pop-up
8. Yes and no buttons in the pop-up is not performing any action