Hi @MaineOffice,
Thank you for posting here in the Community. I'm here to help you restore the company file in QuickBooks Desktop.
You can perform some basic troubleshooting to isolate and resolve the issue. First, please make sure the program is up-to-date to ensure you install the latest maintenance and fixes.
Here's how:
- Click the Help option in the upper-right corner.
- Select Update QuickBooks Desktop.
- Go to the Update Now tab.
- Enable the Reset Update checkbox.
- Press Get Updates.

- After the download, restart QuickBooks.
- When prompted, accept the option to install the new release.
Also, I recommend reviewing the file type of the company file you're trying to open. It should show with a .qbw extension at the end of the file name.
If the problem persists, you can proceed with following the steps in this link: What to do if you can't open your company file in QuickBooks Desktop.
I've attached an article you can use to learn more about how to fix a company file using the QuickBooks File Doctor tool: Fix company file and network issues with QuickBooks File Doctor.
Keep us posted if you need anything else regarding the process. Have a great day.