Hi there joanne,
If you're not able to successfully restore the company file in your QuickBooks 2018, we can open the file in your 2015 QuickBooks version and fix the error from there.
Let's start with restoring your 2015 backup file in the QuickBooks 2015 version. Once done, you can Run a Verify and a Rebuild. Verifying the file helps detect the damaged data and Rebuilding it fixes the damaged data detected.
To Verify:
- Click File at the top menu.
- Go to Utilities then select Verify.
To Rebuild:
- Click File at the top menu.
- Go to Utilities then select Rebuild.
Once done, try restoring the company file in your QuickBooks Desktop 2018. If you're still stuck in the verifying stage, run the QuickBooks File Doctor: Fix your company file or network (US, CA, and UK).
If you're still getting the same issue, please contact one of our Technical Support Specialists. Here's the link for QuickBooks support: https://help.quickbooks.intuit.com/en_US/contact
- Select QuickBooks for Windows.
- Select your QuickBooks for Windows version.
- Select a topic.
- Click on the Get Phone Number button.
If there's more that I can help you with, don't hesitate to leave me a message below.