It happened first in-browser, then I downloaded it to see if it worked that way, which was not the case. I believe there was an error message window when I downloaded, I can try again and send the message (assuming i'm remembering correctly) if you'd like!
I just gave it a shot and had no issues this time... I wonder what's changed? Not sure how much more I can investigate, but I'll let you know if I figure it out. If not, apologies for wasting your time on it!