The "advanced upload of files" assignment type does not permit re-submission after grading -
once the assignment is either (1)submitted for grading, or (2)graded, even if left in draft,
the upload form is no longer provided to the student.
It would be helpful to provide an "allow re-submission of files" option.
The other features of the "advanced upload of files" assignment type are quite welcome, but it is unfortunate that the resubmit option has been lost.