There's one FAQ page that suggests downloading and installing the manual update for that problem:
https://ttlc.intuit.com/community/bugs-and-error-messages/help/error-1603-a-fatal-error-occurred-dur...
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But I know the manual update may be one update behind...but try it anyhow:
https://ttlc.intuit.com/community/updating/help/manually-update-turbotax-for-windows-software-basic-...
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After that, uninstalling TTX entirely and re-installing may be your only option....find your installation code first though.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
