When an administrator or instructor tries to delete a submission from a student when they save changes they receive an error message that Nothing was submitted.
STEPS TO REPLICATE
1) Navigate to this assignment
2) View all submissions
3) Scroll to a student's submission
4) Click on "Edit"
5) Select "Edit submission"
6) Select the submission from the dialog box
7) Click on "Delete"
8) Click on "Ok"
9) Click on "Save changes"
10) Warning pops up "Nothing was submitted"
When the instructor deletes the submission from the student and try to save the changes they receive the message "Nothing was Submitted". This was tested on core Moodle with the same results. This is not related to Turnitin. It happens with all assignment activities. It doesn't seem to be a permission issue because the item does delete item; the error comes when user tries to save the changes of the delete.
As a workaround, if the the student has a new submission they would like to submit. They can add the new submission after the original one is deleted.
When the teacher removes the submission it should be removed and the changes should be saved.