QuickBooks suddenly won't let me open up my other company file.

Which QB Desktop year version do you have?

Have you tried to run QB ToolHub to check the file?

Hello there, @pixie68. I'll provide additional troubleshooting steps to access your QuickBooks Desktop (QBDT) company files seamlessly.

First off, have you encountered a specific error message while trying to open your other company file? Or you're currently opening a company file and trying to access the other company?

Nonetheless, let's ensure you have the latest release of the program. Then, we can run Quick Fix my Program from the QuickBooks tools to repair your program. It's designed to fix the problems with functionalities that aren't working. Here’s how:

1. Close your QuickBooks account.
2. Download the most recent version of the QuickBooks Tool Hub, then save the file somewhere you can easily locate it.
3. Open the file you downloaded (QuickBooksToolHub.exe).
4. Follow the on-screen steps to install.
5. When the installation finishes, open the Tool Hub on your Windows desktop.
6. Select Program Problems and click Quick Fix my Program.
7. Run the QBDT program to open your company file and check your register.

If the issue persists, you can follow Solutions 2-5 laid out in this article for additional troubleshooting steps to fix this issue: QuickBooks Desktop won't open.

I'm always around to lend a hand if you need further assistance with accessing your company files in QBDT. Stay safe!