Let me guide you on how you can fix this so you can back up your data, Paul.

Sometimes, new software and outdated versions are one of the reasons that can cause backup failures or errors. But, there may still be other underlying reasons why you're backup stores on the temporary file.

You can download and install the QuickBooks Tools Hub to fix this. To do so, follow the steps below:

1. Close QuickBooks.
2. Download the most recent version (1.6.0.3) of the QuickBooks Tool Hub. Save the file somewhere you can easily find it (like your Downloads folder or your Windows desktop). Note: If you've installed Tool Hub before, you can find out which version you have. Select the Home tab.  The version will be on the bottom.
3. Open the file you downloaded (QuickBooksToolHub.exe).
4. Follow the on-screen steps to install and agree to the terms and conditions.
5. When the installation finishes, double-click the icon on your Windows desktop to open the tool hub.

If you're unable to locate the icon, do a search in Windows for QuickBooks Tool Hub and select the program.

Then, run QuickBooks File Doctor. Here's how:

1. From the tool hub, select Company File Issues.
2. Choose Run QuickBooks File Doctor. It can take up to one minute for the file doctor to open.
   If the QuickBooks File Doctor doesn't open, search for QuickBooks Desktop File Doc and open it manually.
3. In QuickBooks File Doctor, locate your company file from the drop-down menu. If you don’t see your file, click Browse and search to find your file.
4. Then Check your file (middle option only) and then Continue.
5. Enter your QuickBooks admin password and then Next.

The scan time depends on your file size and may take up to 10–15 minutes. This may say it was unsuccessful even if it fixes your issue. 

Once the scan finishes, open QuickBooks, and your company file, then proceed with creating the backup.

However, if the issue persists, I recommend reaching out to our support team to take a look and investigate further. They have the tools to pull up your account in a secure environment.

Moreover, I have some tips that can be helpful in what you can do with your data once QuickBooks is discontinued. To know more details, go through this article for more details: QuickBooks Desktop 2020 Service Discontinuation Policy.

If there's anything else that you need when backing up your file, let us know so we can get back to you as soon as possible. Have a great day!