Checking my return, it says Sch IN-W: Col D-State Income must be entered. What does this mean? I earned all my income in the state of Indiana and entered this from my W-2

Column D on Schedule IN-W is state income as listed on a withholding form like a W-2. See this sample (link in the first paragraph). 

Did you enter a W-2 or a 1099-R? The state income should have come automatically from these forms.

Any chance that that you have withholding boxes that have an "IN", but no dollar amounts?

Thank you!!