Hello and welcome to the Community, @jpmc_bc.
I'm here to get you moving in the right direction towards completing your payroll setup in QuickBooks.
This error usually occurs if you're missing information somewhere on your employee's setup. Be sure to review all your employee's data including the inactive employees to complete the setup. If you've moved from QuickBooks Desktop to QuickBooks Online and you can't move on to the employee's taxes section, it's likely because you need to inactivate an employee.
You can check this guide to fix this: Troubleshoot employee set up.
However, if you received the "We hit a snag" error, please reach out to our Online Support so they can access your account in a secure environment. They have tools to review your payroll information and locate other missing data that is required during the payroll setup.
Keep me posted on how it goes. I'm here to ensure you'll get all the help you need.