Hello there, @sb3421.
I appreciate you downgrading your MacOS to use QuickBooks Desktop (QBDT). Since it still doesn't work, let's clean install your QuickBooks Desktop for Mac so you can open and work with it. Let me guide you through the process.
Before doing so, you should have a backup copy of your company file so you can use it to restore when reinstalling the software.
Firstly, let's uninstall your QBDT for Mac. Before uninstalling, have your QuickBooks Desktop download file (or installation CD) and license numbers ready. Here's how:
- Close your QBDT for Mac.
- Go to the Finder menu, then select Applications.
- Drag the QuickBooks icon to the Trash.
Then, remove the QuickBooks PLIST files. To do so, you can follow the steps below:
- Go to the Finder menu.
- Hold down the Option key, then select Library.
- Open the Preferences folder.
- Find PLIST files that contain com.intuit.QuickBooks20XX, then move them to the Trash.
- Note: XX is the QuickBooks version you’re using.
- Empty the trash.
Once done, restart your device and reinstall QBDT for Mac.
Just in case you want to know more about QuickBooks for Mac, you can check out this user's guide for more guidance: QuickBooks Mac Plus User’s Guide.
Come back to this post if you have other concerns or follow questions about this. I'll be around to provide further assistance.
