A teacher assigned their students a quiz. They wanted students to retake the quiz and imported it again.
The second import rewrote over the quiz and the student grades.
Can original grades be recovered?
Does your institution have a test or beta environment alongside your main Canvas system? If the URL of your Canvas environment is yourschool.instructure.com then your test or beta system would be at yourschool.test.instructure.com or yourschool.beta.instructure.com
If one of these exists for you then it will contain a recent copy of your entire system, so the grades might still be in the copy of the course there.
For future reference, if you want your students to take a quiz again, you can keep the original quiz and just use the "moderate" option to give them another attempt:
Brian, I agree with Steve that the first thing I would try is the Canvas Beta Environment (the data gets refreshed every Sunday) - How do I access the Canvas beta environment? If the quiz scores aren't there, then the next thing I would do is contact Canvas Support. I've had faculty lose grades before and Support is normally able to retrieve them.
As a side note, if the Instructor wanted the quiz to count twice in the gradebook, the easiest way to copy the quiz is to import it from the same course. Using this guide - How do I copy content from another Canvas course? - when you get to the part where you select the course to import the content from, select the course you are working in (the one where the students have already taken the quiz) - yes, this seems wrong, but you are going to copy the quiz back into the same course. Then make sure and click "Select specific content" and then select the quiz that the Instructor wants copied.
Hope this helps and hope you are able to retrieve the quiz scores!
Retrieving data ...