I'm co-teaching a course, and one instructor imported an Canvas quiz into his new class, but when the students started taking it, they were telling him it wouldn't let them respond.
He deleted the quiz, wrote it out from scratch, but had the same problem.
I went in under student view and was able to replicate the problem,
The quiz is published, he didn't set any availability dates, the due date in the the future, but neither one of us seems to get this to be able to work.
I can seem to take the quiz in preview mode, but my answers are not recorded.