Thanks for joining this thread, @BeccaTwig. I'm here to ensure you'll be able to get rid of that error to recover the deleted employee seamlessly in QuickBooks Online (QBO).

Once an employee is deleted in QBO, the system will remove all of their info. That said, you'll have to recreate the deleted employee manually. Here's how:

1. Navigate to the Payroll menu and click Employees.
2. Next, select the Add an employee option.
3. Fill in the needed details and click Add employee.
4. Then, select any section to add the remaining employee info.

For reference, feel free to check this article: Add your new employee to QuickBooks Payroll.

Then, to further help you resolve the payroll sync error, I recommend reaching out to our Payroll support team. They use specific tools to pull up your account and fix it. 

The program also offers several reports that you can open to easily track your payroll info, employee details, and business finances. To get started, visit this link: Run payroll reports in QuickBooks Online Payroll. 

Please let me know how this goes. I'm always here ready to lend a hand if you have any other follow-ups about managing your employees in QBO. Feel free to post here again at any time. Have a great day ahead.