I had this same issue (was able to get log in screens for all other brokerages except Fidelity where I only got a blank screen) and posted my issue a couple of weeks ago (I didn't know something had already been posted on this subject). I struggled for weeks, switched browsers, uploaded updates and nothing worked until another user (Ron1000) posted the following solution. I kept changing my resolution until I was able to see the the user sign in and password boxes on the Intuit screen. I typed by information in. Even though it didn't display what I was typing, it took the information and then gave me the login boxes so I could sign into Fidelity. Hopefully this will work for you as well. Here is Ron1000's response
I HAVE THE ANSWER....
It's definitely a TT issue and it basically involves the screen resolution and scale. A TT representative gave me the idea of playing with my screen resolution. I usually use a very high resolution so I lowered to 800X600 which created a really large pop-up but it did come through. It still would not allow me to enter the login and password but at least I can see the box. Next I started increasing the resolution to 1280. I then started playing with the scale and the boxes went live when I reduced it from 150% where I usually keep it to 100%. Everything worked and I was able to download my Fidelity transactions.
