Hello, ACD2.
I'll share additional information about the error message you received after redownloading your QuickBooks Desktop version.
You'll be getting the same error message since you might have used the expired license number and product key. If you wish to keep utilizing the same product information, you can renew it or buy a new one-time license, like Fiat Lux - ASIA suggested.
You can also utilize the trial version for QuickBooks Desktop 2021 to access your company file. I recommend reaching out to our QuickBooks Desktop Support if you don't have the product information for the trial version. You can use this link if you're unable to get into your product: Contact Us.
Once you have all the necessary information on the QuickBooks Desktop 2021 trial version, you can follow the steps in this article to install it on your computer: Install QuickBooks Desktop.
After the installation, you can now restore a backup copy of your company file.
The Community and I will always be here to help you, don't hesitate to add any details below if you need further assistance. Stay safe and enjoy your day.
