I noticed that answering quizzes was throwing an error:
Fatal error: Call to undefined function userpoints_get_vid
that's because I had disabled the Userpoints module without ticking off Enable UserPoints Module Integration in admin/quiz/settings/config (under Addons Configuration).
when I tried to un-check that option, it was greyed out as enabled.
now I understand module dependencies can be quite complicated, but I think it'd be friendlier if that particular checkbox were disabled automatically if the Userpoints module were disabled as well. or the quiz in question could call
drupal_set_message() and warn site admins without a WSOD.
what do you think?