Hi, j3ch. 

As mentioned by my colleague @MadelynC that QuickBooks Desktop uses Microsoft programs to run web-based apps. Once the .NET Framework has an issue, QuickBooks may not work properly.

If you're still getting an error after following the steps provided by my colleague above, you'll need to fix it manually. But before that, please check this article link for you to be guided on QuickBooks Desktop errors: Fix QuickBooks Desktop install errors. If you experience the same thing refer to the steps below for your operating system.

For Windows 10, 8.1, and 8.

1. Make sure to close all of your programs.
2. Go to the Windows Start menu. 
3. Type "Control Panel" and click Control Panel.
4. Select Programs and Features.
5. Choose Uninstall a Program. Don't worry, you aren't uninstalling anything.
6. Click Turn Windows features on or off.
7. Find .NET Framework on the list.

Then, check the settings for both .NET Framework 4.5 (or later) and .NET Framework 3.5 SP1.

Note: Steps to fix .NET. Framework 4.5, 4.6, 4.7, and 4.8 are the same.

Check if the .NET Framework 4.5 (or later) checkbox isn't checked:

1. Tick the checkbox to turn on .NET Framework 4.5 (or later).
2. Click OK to save your changes.
3. Restart your computer.

However, if the .NET Framework 4.5 (or later) checkbox is already checked:

1. Tick the checkbox to turn off .NET Framework 4.5 (or later). Don't turn it back on.
2. Click OK to save your changes.
3. Restart your computer.
4. When you're signed in back into Windows, go back to the steps to turn on .NET Framework 4.5 again.

Then, proceed to check if the .NET Framework 3.5 SP1 checkbox isn't checked:

1. Click the checkbox to turn on .NET Framework 3.5 SP1.
2. Hit OK to save your changes.
3. Restart your computer.

Follow these steps if the .NET Framework 3.5 SP1 checkbox is already checked:

1. Click the checkbox to turn off .NET Framework 3.5 SP1. Don't turn it back on.
2. Hit OK to save your changes.
3. Restart your computer.
4. When you're signed in back into Windows, go back to the steps to turn .NET Framework 3.5 SP1 on again.

If the issue persists after turning on or off .NET Framework, I recommend reaching out to an IT professional or Microsoft. The issue may be related to your operating system, not QuickBooks.

You can check out this article for more detailed steps to fix .NET Framework errors on Windows 7: Manually fix Microsoft .NET Framework errors. 

For good practice, I recommend backing up your company files. This way, you can restore them anytime in case of accidental data loss.

You can count on me if you have more questions about managing your QBDT. I'd be glad to help you some more. Take care always.