Not sure there is a way to fix that.
You may have to start over, or use a backup file (if you have one) or see if there is a "Temp" file you can open (A Temp file starts with a "~") .
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Saving a file and having it immediately show as corrupted is very unusual. Make sure you are NOT saving your tax file to a cloud drive, or to a USB key or USB-connected external drive, since saving them to those locations can result in file corruption....not always, but past history shows it commonly happens for those situations. Only create and save your tax files to the main computer's hard drive.
(Back-up copies can be separately copied/pasted to the other drive types cleanly....just not the Saves from within the tax software)
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
