There is nothing in Box D on W-2

[bveneri]

I entered "0" but cannot proceed with my returns on TurboTax.

[MiriamF]

If there is nothing in Box d, then leave it blank.

If that doesn't solve your problem, then delete the W-2 by clicking on My Account > Tools > Delete forms and deleting that W-2. When you type in the W-2, leave that box blank (and any others that don't have entries). You should be able to proceed.