An investigation has been created regarding this error and was forwarded to our Product Engineers. They're now working to fix this as soon as possible.
In the meantime, let's try to access payroll through the Employees menu as a workaround. Here's how:
Go to Employees menu to get to Payroll.
Click Login to Intuit Online Payroll Page.
Enter your credentials.
I also suggest contacting our Support team and provide this investigation number INV-35925 so they can add you to our notification list. This helps our Engineers know that number of users affected by the issue. Here's how to reach them:
Sign in to your account and click the Help icon located at the top.
Select Contact Us at the bottom to connect with out live support.
An email notification will be sent to you once this has been resolved. I'll also inform you here when we get the update as well.
Thanks for your patience while we look into this. Please let me know if you have any other issue or concerns, and I'll get back to you right away. Have a good one.