This problem is not solved! I use Windows 10. The computer is relatively new. The years 2016 - 2018 work fine.

I have tried both the download 2019 CD and the install from 2018, and each time, I see a blank sign-in mask with no fields for either my User ID or my password. The program effectively is frozen with no ability to log in. My firm already exists. 

Why doesn't Intuit have moderators who review these posts and offer solutions? At these prices, we shouldn't have to hope that some amateur sleuth figures out the solution for us.  

Another bad start to the tax year for Intuit!

I was on the phone with support for 1.5 hours today and did everything they suggested but I still can't get the log in screen.  The support person gave up and told me to hire an IT person.  This is ridiculous.  I last logged in on 1/3 and needed to log in today but couldn't.  Something is wrong and I'm at wits end!

Software now working. I spent close to an hour on the phone with tech support. We re-installed the software but the problem persisted. My Windows 10 was up-to.-date. I had already added three trusted sites to my Internet Options/Security (IE) based on information found here, but the support suggested adding a fourth trusted site. We were cut off, but the next morning, after running a ProSeries update, the software works. I'm not sure whether the trusted sites cured the problem, but here they are:

*.intuit.com

*.intuit.net

*.intuitcdin.net

*.proseries.com

I worked on this log in issue for 5 hours the other day.  I added those same trusted sites too while on the phone with support for 1.5 hours and it didn't help.  Finally, after working on this and restarting my new laptop with Windows 10 multiple times I got the log in screen and everything has been fine.  I honestly think Intuit had a problem and fixed it.

1. if you right-click on the prowin19 folder and select properties.
2. Select the Security tab. 
3. Select the Advanced button.
4. Do you see anything that says "Integrity level set to low"