Quickbooks Stopped Working

Which QB Desktop year version and Windows OS?

‘22 and Windows 10

You have Company File A and Company File B, correct?

Open the sample file and save it as Company File C.

Try to switch between A-C, B-C, and other scenarios. Did you encounter the same problem with ALL scenario?

Hello there, @TV Bent. Thanks for posting here in the community. I'll help you with switching from one company file to another successfully. 

There may be times you'll encounter difficulties when transferring from another company file due to outdated software. To fix this, I recommend keeping your QBDT up to date. Note that Quickbooks will automatically download updates once it is available. See the Update available at the top right corner. Follow the steps below as a guide on how to install it.

QBDT for Windows:

1. Click Update available and select Install now.
2. The process of installing might take a while.
3. Once installed, open QBDT.

QBDT for Mac:

1. In the QuickBooks menu, choose Check for QuickBooks Updates. 
2. Click Install and Relaunch.

For more details on installing the desktop update, visit this article as a reference: Update QuickBooks Desktop to the latest release. 

Furthermore, if the issue persists, I suggest downloading a QuickBooks Tool Hub and running Quick Fix my Program and Quick Fix my File from the QuickBooks Tool Hub. 

Moreover, scan this article in the future to understand more about handling balance issues inside QBDT: Fix beginning balance issues in QuickBooks Desktop. 

Don't hesitate to reply on the thread for more queries. I'll get back to you. Take care!