Some customers do not have an Employer State Identification Number listed in Box 15 on the W-2. This is causing an error when going through Federal Review.
If employed and living in a state without income tax, delete the state abbreviation, and leave all the state boxes blank.
If your state does have income tax, contact your employer for a corrected W-2 with their ID number.
As a last resort, you can enter the federal tax identification number here.