I was having the same problems as people have described on this thread, and all of them were fixed by disabling my antivirus software just before starting the TurboTax Updater. Apparently, the Bitdefender Firewall was blocking TT from accessing the internet, and that may have messed up my installation (Windows download) even before the failed updates totally "broke" the program. I only needed to have it disabled for 2-3 minutes because I started TT first (which took forever to launch as it was running incredibly slow), cancelled the Auto Updater and waited another long time for the program to relaunch. I closed my browser and all open programs, disabled Bitdefender, then selected Check for Updates. Remarkably, it was already running 10x faster at this point. The update only took a short time, and installed "Critical" Program and Tax Form updates released on 1/13/20.
I immediately enabled my antivirus protection and opened the tax return I had started earlier before everything stopped working. Before the update, it took well over a minute just to open the return Now it opened up quickly, all the forms I had created were back in place, and everything was working again. That's it. I didn't have to reboot or do anything else. Had I seen this thread earlier, I probably would have tried running the Updater in Admin mode first because that sounds less risky, but I read about the potential antivirus issue somewhere else, so that's what I did. It's possible that running as Admin may have also solved the problem, but I can't say. One last thing, I went back and added the turbotax 2019 installer.exe file to the exclusions folder in Bitdefender so that it knows it's a safe application. Maybe the TT program update already fixed this, but just in case.
