Hello there, @Heinz2.

I'd recommend getting in touch with our Customer Support for the fix. This way, our data service team can further check if they can recover or retrieve the lost data.

Here's how:

1. Go to the Help menu.
2. Select QuickBooks Desktop Help. 
3. Click the Contact us button. 
4. Type a brief description of your concern.
5. Hit Let's talk, and then choose a way to connect.

You'll also want to check our support hours page to see when our support will be available. 

For additional information about the Data Services team, check out the following article. It also contains detailed steps regarding the type of files you can upload: QuickBooks Data Services FAQ.

You can visit this link about recovering data in QuickBooks: Recover lost data with QuickBooks Auto Recovery.

Let me know if you need further assistance with your lost data. I'm always here to help.