It likely will continue to say there is not a submission since the student did not submit anything.
Sometimes, for the assignments, I will set it to file upload and ask students to submit a picture AND turn it in to me. I tell them they are submitting a picture just in case the paper gets misplaced.
Another option to consider, if you have access to a scanner, is have students scan their work and submit the file. You could even get a portable page scanner (I've liked the Brother DS-720...not sure if still being made). Then they just plug it into their computer, hit the button to scan, and submit their file.