I was getting the same 1648 Error and could not update my TurboTax 2020 Software but I had already filed my taxes. The issue occurred after a major update from Windows 10 that TurboTax 2020 would not update. I tried the manually update file option and that did not work (originally I may have started with a 1603 error). I was then led to a .Net Framework Issue but it was up-to-date. Hence, I rolled back my Microsoft Updates and then that just made everything worse - I could not open TurboTax at all anymore and got a sequence error if I tried to open the software and/or open the tax file. Every time I tried to install and/or uninstall I got the 1648 error. I did everything in all of the articles but never got to this article until I googled the error.
Running the Tool does not remove your tax returns and it fixed my ability to Install/Uninstall TurboTax 2020 so that I can now re-install TurboTax 2020 and get to my return within TurboTax (and updates successfully ran). I found this article after I spent approximately 3 1/2 hours on the phone with the sweetest Intuit TurboTax support analyst but she only found what I found. I don't know how we did not find this article in the TurboTax support. Thanks for the Microsoft Tool - I will definitely safe that linkage for future reference!!!
