I'm using Turbotax 2020 home and business, desktop version. It has worked before and my return is almost done. I haven't been able to start Turbotax the last few days due to this issue.
The only thing I can think of (if using a Windows computer) is to shut down and reboot your computer....there have been a few Windows updates recently, and partially-installed update has been known to cause problems with TTX.
I just tried rebooting and then started TurboTax again. It again tried to install updates and I got the following error (same one I keep getting):
Failed to install update. Microsoft Installer error. 1603, Fatal error during installation.
Check for solution.
When I try clicking the link for "Check for solution," it can't find one.
I clicked OK on it and then it says "restarting Turbotax" but it didn't ever start again, and Turbotax had just disappeared.
There's one FAQ page that suggests downloading and installing the manual update for that problem:
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But I know the manual update may be one update behind...but try it anyhow:
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After that, uninstalling TTX entirely and re-installing may be your only option....find your installation code first though.