I run a distance course in basic music theory, in which there are only instructional animated videos followed by a series of practice quizzes, divided to progressive modules. I did set prerequisites on modules to make sure that the students only progress to the next when the previous one is completed. What I only realized 2 days after the course opened was, that I should also add requirements within every module in order to clarify when a module is actually "complete" - in my case, it suffices that they view the pages and submit the quizzes, regardless of their grade.
So I added the requirements and decided not to lock the modules, so as not to "punish" students for my own mistake by forcing those who already submitted quizzes to submit them again. But I'm still not sure what will happen with students who viewed quizzes without submitting them prior to my change of requirements. Will it be visible to them in some way that they need to go back and submit missing quizzes in order to proceed with the course? Or will canvas consider them to have already met the requirements of that incomplete module, (because there weren't any when they did it)?