QuickBooks for Windows Sync Error: You cannot create subaccounts while your accountant is working on an Accountant's Copy

Why the Sync Error occurs

This error occurs because QuickBooks does not allow the addition of a new subaccount to an existing account while the Accountant's Copy is pending.

How to Fix the Sync Error

Once the Accountant's Copy is no longer pending in QuickBooks, the subaccount created in Bill.com will sync.