Thank you for
reaching out on the community and telling us about your issue. I do apologize for the issue you're having. Is this happening each time you open quicken? Are you still able to get in the program or is it limiting your access as well? If you wouldn't mind could you take a screenshot of the blank screen. On another note I do occasionally see this when antivirus programs are blocking quicken access. If you do have an antivirus I would try disabling it for a little bit and see if you're able to sign in afterwards.
Once you get a chance could you give us some more details and we'll see what we're able to try.
It occurs most of my attempts to open Quicken. It does not allow me to access my files at all. I tried to take a screen shot and I think I was able to attach it.
My anti virus program is McAfee and I've had the program for 2 or 3 years with no problem until very recently.