I had this problem last Sat Apr 5. Checked everywhere on my computer and the boxes that uFile suggested, but nothing needs to fix. At first, I thought maybe CRA server was down for maintenance or something and didn't bother to keep trying after I tried the download 3, 4 times.
Today is Apr 13 and the same error is still showing up. I deleted my file for the entire family and started from scratch - no luck. I logged in CRA my account via Google Chrome. It worked as expected. CRA doesn't seem to be the cause here.
uFile - why so many people have this problem in 2019 when previous years were fine? Any suggestion?