I was having the same problem. I finally closed TurboTax and then switched my default browser to MS Edge. I then restarted TT and tried the download again. This time it worked. So, the problem is either TT or Fidelity do not have their processes set up to use all of the browsers. If you're having this problem, make sure MS Edge is your default browser, and the download should work. The easiest way to make Edge the default, is to manually start Edge, and when it asks if you want it to be the default, just say yes. When you're through, you can change back to your regular browser by following the same procedure.
