Lyn, I just clicked on this link and got the access denied message as well. I'd recommend reviewing the directions on this Google guide to see what you're missing - Share files from Google Drive - Computer - Docs Editors Help
Then if you want to check it, go to a different browser than the one you are logged into Google on and see if the link works. So make sure you are NOT logged into Google on the browser and then see if you can get the link to work - which will be similar to what the students are trying to do.
Hope this helps! Kona
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