Hey info139,

I'm happy to see you've upgraded to 2020! Having the most recent version ensures you'll always enjoy the best QuickBooks experience yet. It's our goal to make upgrading as seamless as possible, and I want to make sure you can access your client's books. I'll be happy to help you get up and running with the 2020 version.

This issue can typically be resolved by signing into QuickBooks Desktop as an admin user. You should be prompted to sign in as soon as you open QuickBooks, or when selecting your client's backup file. Just have the administrator enter their credentials, and you're all set.

If you continue to receive this error after signing in, please reach out for some real-time assistance with a trained agent. These agents will be happy to help you, and are great help in these situations. They have the ability to look into the specifics your account to quickly solve errors like this. You can read about our support policies here: Intuit QuickBooks Desktop software support policies. 

Don't hesitate to reach out. I want to make sure you're able to take advantage of this upgrade.