I recently got an e-mail from my professor saying that I had not turned in any of the assignments for his class and I was in danger of failing the class. I looked on my canvas page and saw that all of my past assignments had been given zeros and were labeled "no submission". I am 100% certain that I submitted all of these assignments, and that I submitted them to the correct place (I checked all my other classes and assignments to make sure). I vividly remember attaching three files for this one lab report and seeing "submitted" and the green check mark, however when I went to check just now, not a single assignment was there. I have explained to my professor, resubmitted all the assignments, and hopefully he will give me grace (I will not graduate on time if I fail this class). What might have happened that caused all my assignments to disappear? Is there a way to keep this from happening again?