[Assignments] corrupt file warning

[kvjansen]

Problem statement:

Roughly 1 - 2% of student submissions turn out to be corrupt files. Teachers then must chase down the student to receive a good file, and it's impossible to establish responsibility for work submitted incomplete or late.

Proposed solution:

Canvas provides students a receipt when uploading to an assignment. Please include a warning on the receipt when an uploaded file is corrupt or just random characters.

User role(s):

instructor