Update causing damaged backup file

ME84

I did a backup on 8/11/24 Quicken did an update on 8/14/24 which should have created a backup then as well. After the update on 8/14/24 the file from the 11th is damaged. I have to restore back to July to get a nondamaged copy. This means I have lost 30 days worth of invoices with no paper trail to collect funds from customers. Quicken customer service says there is no way to repair the damaged file or reverse the update and get all the information back. Looking for assistance with this process.

NotACPA

How did you determine that a file, that wasn't even open at the time of the update, was damaged by that update?

As opposed to the MUCH more likely explanation that latent damage in the file was disclosed by the update.

And, why couldn't you use the backup that was created on 8/14? If it was damaged also, that would support my "latent damage" explanation.

And, what sort of damage was it? Did you try Validating, or SuperValidating, the file to repair it?