Hi there, @Anonymous.

I'd be glad to help you fix the System Exception Error. Since you’ve done using the QuickBooks Tool Hub, there are two more workarounds you can perform to fix this.

You can clean install QuickBooks Desktop (QBDT) by uninstalling and reinstalling it. Or you'll need to check if you have appropriate user permissions to C:\ProgramData.

You can begin with downloading the latest release of the QBDT program. Then, create a backup copy of the company file to keep a copy of your previous transactions. This procedure fixes known issues of the software and improve its overall performance.

To install the release:

1. Go to the Help menu and select Update QuickBooks Desktop.
2. Choose the Update Now tab, then mark the box for Reset Update to remove the previous download.
3. Click on the Get Updates button to start the process and click OK to continue.
4. When the QuickBooks Desktop Information window appears, click OK and then restart your QuickBooks to kick-off the installation. I've added some screenshots for additional reference:

After completing the following steps, you can start creating a backup. Then, uninstall the desktop program. You can go to the Control Panel to find the application.

1. On your keyboard, click the Windows Start menu and search for Control Panel.
2. Select Programs and Features or Uninstall a Program.
3. Choose the version of QuickBooks Desktop you're having problems with from the list of installed programs.
4. Select Uninstall/Change and follow the on-screen instructions. Ensure that you are the Windows Admin to do this process.

Once done, you can follow the steps in this article to do a clean install: Clean install QuickBooks Desktop.

Also, you may consider checking this article to know more about the other option to fix this error: Fix System Exception errors.

Please don't hesitate to tag my name in the comment section if you have other questions or concerns. I'd be happy to lend a helping hand. Take care.