When you successfully submit your work to an assignment before the due date you will be presented with a confetti celebration and then see a green checkmark in the Submission window. You can turn off the confetti celebrations by following the "Manage Celebration Animations" documentation. With that said, you must wait for that green checkmark. Don't browse away from the page while your assignment is being uploaded:

If you wait, but don't get the green checkmark, here are some things to try:

Clear your browser's cache & cookies.

  1. Update your browser to the latest version.
  2. Use Incognito mode, which disables browser extensions.  Chrome instructions.  Firefox instructions. As of 2017/1/16, the LastPass extension to Chrome is known to cause problems uploading to assignments.
  3. Try a different browser.
  4. Try a different computer.