There are very few forum threads about file corruption of the *.tax2025 data file with every file save. You didn't say if you are using a Windows 11 PC or a Mac (Sonoma 14 or higher.) I'm suspicious it may be a Mac, however. If so, have all the computers over the 5 years been Mac?
If you are using a Mac, is your data file unknowingly being encrypted in the keychain? TurboTax will sometimes say a file is "corrupted" if it's password-protected/encrypted.
