You can try entering 0 in Box 20, to see if that helps to resolve this issue. Box 20 and Box 19 go together, so to say. If you have an amount in box 19, but nothing in box 20, this is a problem. This could be why TurboTax will not let you proceed. With an amount in box 19, box 20 needs a locality name that the amount in box 19 was paid to. This is usually a city income tax or sometimes state disability payments. In any case, there needs to be a locality name in box 20, if box 19 includes any amount. Please see the Word Doc I have attached that explains every single box and code on your w-2. You should contact your employer to inquire about the mistake.
